Tory MP John Penrose has resigned as the PM's anti-corruption champion ahead of this evening's confidence vote.

He says it's clear that Boris Johnson broke the ministerial code over the row about Downing Street parties during lockdown.

"That’s a resigning matter for me, and it should be for the PM too," he says on Twitter, along with his letter of resignation.

The BBC has seen a copy of the letter, external Boris Johnson has sent to his MPs ahead of the vote of confidence.

He writes that the ballot is a chance to "draw a line under the issues our opponents want us to talk about" and focus on "what really matters" to voters.

Appealing directly to his MPs, he says with their support the party has a "great prize within our grasp" - the chance to put "an end to the media’s favourite obsession".

"We can get on with the job without the noises off," he adds.

Take a look at the full letter below.

What could tonight's numbers be?published at 11:10 British Summer Time 6 June 2022

11:10 BST 6 June 2022

Iain Watson
Political correspondent

Several of the long-standing critics of the prime minister are confident that around a third of their fellow MPs - between 120 and 130 - will definitely vote against Boris Johnson tonight.

The whips believe they can keep the number under 100.

But rebel backbenchers believe the number of ministers and ministerial aides who join them will be crucial.

One of them told me that No 10 was making a "bold assumption" if it thought the so-called payroll vote would remain loyal in its entirety.

The feeling amongst his internal opponents is that if Boris Johnson wins only narrowly - some say if 150 MPs abandon him, while others say that number would need to be higher - his position would be impossible.

But some of his supporters scoff at this. They say he would be determine to fight on even if he wins by a sliver.

Another leadership challenge would be a year away (unless the rules are changed) and he could embark on a reshuffle, bring forward tax cuts, and have the opportunity to change the narrative if he grasps the cost of living crisis.

Former transport minister Steve Norris has a word of advice, external for current Tory MPs about making use of the secret ballot.

"Be as loyal as you like on Twitter and then do the sensible thing if you want to be re-elected," he says.

He says that advice applies to any Conservative MP with a majority of less than 10,000. "Otherwise you're toast," he warns.

Former Health Secretary Jeremy Hunt, tipped as a possible leadership contender, has said he will be voting "for change" in this evening's ballot, external.

Hunt says he wanted to avoid a confidence vote during the Ukraine war, but the party must now decide its future.

"Having been trusted with power, Conservative MPs know in our hearts we are not giving the British people the leadership they deserve," he says.

"We are not offering the integrity, competence and vision necessary to unleash the enormous potential of our country.

"And because we are no longer trusted by the electorate, who know this too, we are set to lose the next general election."

There's more opposition reaction to the confidence vote now.

Sir Ed Davey, the Lib Dem leader, described the news as signalling "judgement day for Conservative MPs and their sleaze-ridden prime minister".

He said, external: "If they fail to sack Boris Johnson, it will be an insult to all those who made sacrifices and suffered while he partied."

Elsewhere, Labour's Shadow Health Secretary Wes Streeting said it was "about time" the vote happened. He also said he "saluted" the Tory MPs who submitted letters, calling for the vote to happen.

"I hope the Conservatives will search their consciences before the vote tonight," Streeting told the BBC, adding the vote was a matter of "no confidence or no backbone".

Image source, Reuters

Steve Barclay - the Downing Street chief of staff and a firm ally of Boris Johnson - has warned it would be "inexcusable" for the Conservative Party to drop its leader less than three years after a landslide general election victory.

"It is crucial that we show people we are delivering on the change they voted for in 2019," the MP for North East Cambridgeshire wrote on the Conservative Home website., external

"If we continually divert our direction as a Conservative Party – and by extension the government and the country – into a protracted leadership debate, we will be sending out the opposite message."

Work and Pensions Secretary Therese Coffey tells the BBC she expects Boris Johnson to be endorsed by Tory MPs with a "significant majority" this evening.

She says MPs "won’t want the chaos of some destructive, divisive leadership contest in the next few months".

Echoing other supporters, Coffey says Johnson has got the "big calls" right on issues such as Covid vaccines and "standing up to Putin".

Asked about polling that suggests 55% of Conservative voters feel the PM is not trustworthy, she says he is focused on the strategic issues.

Coffey says she believes Johnson is trustworthy. "He delivers on the promises he's made to people," she insists.

Scottish Secretary Alister Jack tells the BBC that Boris Johnson has his "full support" ahead of tonight's vote.

"He is showing tremendous leadership as we face major challenges at home and abroad," he adds.

"I have no doubt that my colleagues in the parliamentary party will vote to show their confidence in the prime minister.”

Image source, Getty Images

Boris Johnson is due to make his case to Tory MPs before the confidence vote this evening.

The PM will address backbenchers in private at 16:00 BST, with the vote due to begin at 18:00.

The BBC's political research unit says at least 18 cabinet members have now publicly declared they will back the prime minister in this evening's confidence vote.

It puts the total number of Tory MPs doing so - including Boris Johnson himself - at 50.

We can expect the numbers to increase throughout the day, but the ballot itself is a secret one - meaning those taking part don't have to reveal their decision.

The PM needs at least 180 MPs to back him if he is to remain as Tory leader and prime minister.

The UK could be looking for a new prime minister tonight, after a vote of confidence in Boris Johnson was triggered by Conservative MPs. Here's a quick recap:

• The vote was triggered after at least 54 Conservative MPs sent letters to Sir Graham Brady, the chairman of the 1922 committee of backbench MPs. He said he notified the PM on Sunday
• The secret ballot will be held between 18:00 and 20:00 BST, with votes counted immediately afterwards
• At least 180 Conservative MPs would have to vote against Johnson for him to stand down as party leader and prime minister
• No 10 said Johnson "welcomes the chance to make his case to his case to MPs" and the vote is "a chance to end months of speculation"
• The PM's team have sent a document to Tory MPs saying they should back him in the vote to allow ministers to focus on the war in Ukraine and the rising cost of living in the UK
• Most of the PM's cabinet have publicly declared they will back him in the vote, but other Tory MPs have urged colleagues to vote against him
• Labour leader Sir Keir Starmer called on Tory MPs to "show some leadership" and "get rid" of Johnson

Boris Johnson has made his first direct public statement since news of the no confidence vote broke - on the topic of the long-range missiles the UK is supplying to Ukraine.

Several of his supporters have cited his support for Ukraine as a key reason to back the PM.

Johnson says on Twitter, external: "We cannot stand by while Russian long-range artillery flattens cities and kills innocent civilians. 

"The UK will gift the Ukrainian Armed Forces multiple-launch rocket systems so they can effectively repel the continuing Russian onslaught."

While the PM hasn't directly commented on tonight's vote, earlier a Downing Street spokesman said it was "a chance to end months of speculation and allow the government to draw a line and move on".

On Friday, the prime minister received a mixed reception when he arrived for a thanksgiving service for the Queen at St Paul's Cathedral in London.

As he and wife Carrie Johnson ascended the steps, some of those gathered were heard booing - while some then cheered.

Image source, PA Media

Labour leader Sir Keir Starmer has urged Tory MPs to "show some leadership" and vote against Boris Johnson in the ballot later.

He tells LBC Radio that Johnson has "lost" the country's trust and the public mood has changed with a "general sense that this man doesn't really tell the truth" about "many things".

The opposition leader says that while many in his party suggest it is "good" for Labour if Johnson stays due to him being "so damaged"; it is in the national interest for Tory MPs to "get rid of him".

He accuses Johnson of attempting to "cling on" as prime minister and of being "distracted" from helping families struggling with the soaring cost of living.

Starmer warns that even if Johnson wins tonight's vote, previous examples of Conservative prime ministers surviving the ballot indicate "this is the beginning of the end", with the "damage...already done".

Confidence votes almost always bad news for leaderspublished at 09:49 British Summer Time 6 June 2022

09:49 BST 6 June 2022

Chris Mason
Political editor

It’s been coming. The festival of guesswork, the orgy of speculation. Not even the Platinum Jubilee could dial it down.

The simple truth is the Partygate row has incensed lots of people and a growing number of Conservative MPs felt it was behaviour that was impossible to defend.

But this is more than just wine and leaving dos. It’s what it says about the prime minister’s character that unnerves so many MPs.

Some are blunt: either they remove Boris Johnson or the electorate removes him - and them - from government at the next election.

But plenty - including the rebels - expect Boris Johnson to win tonight.

But an arithmetical win is not the same as a political one. Theresa May won a confidence vote easily, but was gone within six months.

What we will get tonight is an indisputable number: the number of Tory MPs who want the prime minister out. It’s a number that will hang around Boris Johnson’s neck for the rest of his time in office.

He will argue other numbers matter far more: the nearly 14 million people who voted Conservative at the last election. The whopping majority he won.

But make no mistake: confidence votes are almost always bad news for political leaders.

Andrew Bridgen, MP for North West Leicestershire and vocal Brexit supporter, tells the BBC that he will be voting against the PM, saying the public are "exasperated" with Partygate.

He said the row over Boris Johnson breaching lockdown rules and allowing further breaches by his staff is likely to drag on. "I don’t think people are going to forgive and forget," he says.

Bridgen claims that "there has been quite a lot of intimidation within the party to suppress the letters" which triggered the no confidence ballot but says the PM's negative poll rating is a "drag on the ticket".

"It’s not normal for a Conservative PM to be booed outside St Paul’s Cathedral," he says.

Although he says Johnson "may well win", he warns backbenchers may seek to change the rules for another no confidence vote within the year, saying they threatened the same against Theresa May.

"We have to be ruthless otherwise we’ll end up with a socialist in power," he says.

Image source, UK Parliament

We mentioned earlier that a senior Conservative backbencher said the party would be "spoilt for choice", if it needed to elect a new leader. Let's look a little closer at that.

Sir Roger Gale, who represents North Thanet and is a vocal Johnson critic, refused to "name names" but said he believed there were some "very good alternatives to the prime minister" within the party.

“There is a list of people ... who are likely to run [if Johnson loses the vote]," he told the BBC.

“Any single one of those people in my view would make a better prime minister than the one that we've got at the moment and as I said, I think we're spoilt for choice."

Who those people are, though, remains unclear.

The pool of names likely to run as Johnson's successor has, for months, included everyone from Chancellor Rishi Sunak and Foreign Secretary Liz Truss through to former Health Secretary Jeremy Hunt and Foreign Affairs Committee Chair Tom Tugendhat.

Unlike Theresa May's leadership challenge in 2019, when it became obvious quite quickly that Johnson would replace her, the current PM's possible successor is not as clear cut.

The confidence vote was confirmed just after 8am today. And according to the BBC's political research unit, 16 of the 22 members of the cabinet have already publicly declared they will vote for Johnson to remain Tory leader in the secret ballot being held later today.

Among them, Levelling Up Secretary Michael Gove tweeted: "The PM got the big decisions right on Brexit and Covid. We need to focus now on defending Ukraine, driving levelling up and generating growth."

Health Secretary Sajid Javid told BBC Radio 4's Today programme: "No leader that I've known of my party has got 100% support from every single colleague, but we make decisions through due process openly and transparently, and tonight is an opportunity to put all this behind us and get on with the job."

Ahead of this evening's confidence vote, Boris Johnson's team has sent a message to all the party's MPs, stating why they should support the prime minister. The main points are:

• The government needs to concentrate on the war in Ukraine and the rising cost of living at home
• Boris Johnson is focused on lowering crime, reducing taxes and cutting NHS waiting times
• The PM dealt with the "biggest peacetime crisis in a generation" in Covid, with a rapid vaccines rollout and "unprecedented" help for workers and businesses
• A full Tory leadership contest would lead to "civil war" in the party, benefiting Labour

Image source, .