Back to Sunak now, and he is facing questions. The BBC's political editor Chris Mason says Sunak's colleagues are trying to demolish his record as chancellor, asking him "do you have the stomach for what's to come?"

The former chancellor laughs, before saying he's surrounded by friends and colleagues at this event which gives him the optimism and confidence to run.

And he says he wants to run an "entirely positive campaign".

The most important thing to remember is "we're all part of the same Conservative family", he says.

Kemi Badenoch says: "I will not enter into a tax bidding war and say my tax cuts are bigger than yours.

"The dividing line in this race is not tax cuts, it's judgement."

Back now with Kemi Badenoch, who outlines three main principles: free markets, limited government, and a strong nation state to "prepare for challenges ahead to win for our country".

"If I were prime minister I would be driven by these conservative principles to deliver a fairer, freer and wealthier united Britain," she says.

"The problems run deep and I'm in no doubt about scale of challenge any prime minister will have to deal with.

"The right has lost its confidence and courage. Our ability to defend the free market as the fairest way of helping people prosper has been undermined

"The truth - that a limited government doing less but better is the best way to restore faith in gvoenrment - has been forgotten."

Nick Eardley
Reporting from Sunak's campaign launch

Image source, PA Media

Rishi Sunak is pitching to his party - but also to the wider electorate. He knows that many Tory MPs still love Boris Johnson.

He knows that many voters liked him too. So he’s making clear he respects and even admires his former boss.

But this is also designed to be a speech that delivers what Team Sunak sees as economic realism.

The former chancellor is talking about a grown up conversation with the country about tax and spending.

He says it is not credible to promise both spending and lower taxes. His plan, he argues, is more realistic.

But remember, many Tory MPs and members were deeply unhappy with rates going up under Sunak.

Concluding his speech, Rishi Sunak sums up his long-term plan: tackle inflation, grow the economy, and then cut taxes.

"I am prepared to give everything I have in service to our nation, to restore trust, rebuild our economy and reunite the country," he says.

"I want to have a grown-up conversation where I can tell you the truth. A better future is not given, it is earned."

Back at Rishi Sunak's launch, he says he has "traditional Conservative values" of hard work, patriotism, fairness, a love of family, pragmatism, and an "unshakable belief that we can build a better future".

But - taking aim at other candidates who have promised immediate tax cuts - he says such a move is not credible now.

He says he won't pretend that choices he made as chancellor - or things he voted on - are now not necessary.

Over to another launch - Kemi Badenoch says she wants to be honest about the UK's economic challenge.

"Inflation has made the cost of living crisis acute but the problems go back way further - we've had a poor decade for living standards," she says.

She says the economy is overburdened with unproductive public spending and too many regulations, slowing growth and "clogging up the arteries of the economy".

"There are too many polices like net zero targets with no thought to the effect on industries in the poorer parts of this country," she adds.

Brian Wheeler
Reporting from Tugendhat campaign launch

Image source, Sky News

Tom Tugendhat promises an end to scandal and petty politics and "fresh start".

He talks about "returning to service" and core Conservative values.

He makes too key economic pledges - cutting fuel duty by 10p and reversing the National Insurance rise.

Tom Tugendhat is pushing for a "clean start" for the Conservative Party - saying the Tories desparetly "need unity" instead of "faction".

"Families across the UK are facing a crisis," he says.

"For so many there is more month than pay [i.e. monthly pay does not stretch far enough]. There is division in our politics, an economy saddled with debt and despair about our future.

"This is a defining moment for us, our country and our party. It will test the values on which we stand."

Image source, .

Brian Wheeler
Reporting from Tugendhat campaign launch

Turning now to one of the other campaign launches - and International trade secretary Anne Marie Trevelyan has introduced Tom Tugendhat.

She says he will "unite our party and our country" and maximise Brexit opportunities.

"It's time for a fresh start, it's time for Tom," she says, to applause from his supporters

At his launch, Rishi Sunak begins by saying Boris Johnson is one of the "most remarkable" people he has ever met - adding he has a "good heart".

The former chancellor - whose resignation last week triggered the prime minister's downfall - says he disagreed with his boss frequently - and that he was flawed "like the rest of us".

But he says: "I will have no part in a rewriting of history that seeks to demonise Boris, exaggerate his faults or deny his efforts."

Transport Secretary Grant Shapps has dropped out of the Tory leadership race - instead throwing his support behind the former chancellor Rishi Sunak.

In a tweet, external, he said: "Huge thanks to my team for helping to pull together my leadership bid in literally no time!

"Amongst a field of brilliant candidates, I've spoken to Rishi Sunak who I believe has the competence and experience to lead this country."

Deputy Prime Minister Dominic Raab has taken to the stage at Rishi Sunak's campaign launch to endorse him for leader.

Raab says Sunak's got what it takes to steer the UK through tough economic times.

He's a "true Conservative... imbued with the values of enterprise, hard work, and family".

Rollercoaster day aheadpublished at 11:04 British Summer Time 12 July 2022

11:04 BST 12 July 2022

Chris Mason
Political editor

As the candidates begin their pitches, prepare for a rollercoaster day.

Different campaign teams are imagining not just how today might play out but also how things might look in the next 24 to 48 hours.

Who would they like to be prime minister? Perhaps even more crucially, who would they desperately hope isn’t?

That will motivate where defeated candidates or those that drop out switch to.

One little detail worth mentioning too. What happens when the field narrows? Could we have a new prime minister as soon as next week? Possibly, but unlikely.

When there are a handful of candidates left, around four, the Chairman of the 1922 Committee of Conservative MPs, Sir Graham Brady, will ask each of those left to commit to taking part in the run off of the final two, if they make the final two.

This would take the contest to the party in the country, the party membership.

This is to try to prevent a repeat of 2016, when Andrea Leadsom pulled out and Theresa May became Prime Minister without the Tory membership being consulted.

Sir Graham believes asking them each for an explicit promise that they would run the race to its full conclusion is a better option than bringing the third placed candidate back from the dead in the event of one of the final two backing out.

But: a lot can change numerically and psychologically between there being four candidates and two and no one can compel someone to stay in a race they’d rather not take part in.

Plenty of party members will of course hope they get a say — and are handed the awesome responsibility of choosing our next Prime Minister.

Brian Wheeler
BBC News

Tom Tugendhat’s supporters - including former ministers Damian Green - are taking their seats for his official campaign launch in the Atrium at 4 Millbank, opposite parliament.

There is an expectant buzz in the air.

The slogan “Tom - A clean start" is on prominent display.

"It sounds like a cleaning fluid," mutters one audience member.

Image source, PA Media

The bookies' favourite to be next Conservative Party leader, and therefore prime minister, is Rishi Sunak.

Sunak - who resigned as chancellor a week ago, after losing confidence in Boris Johnson - formally launches his campaign in the next few minutes.

We've been sent extracts of the speech he's due to give. His approach differs from some rivals, as he doesn't seem to be promising immediate, specific tax cuts:

• "We need a return to traditional Conservative economic values - and that means honesty and responsibility, not fairy tales"
• "I have had to make some of the most difficult choices in my life when I was chancellor, in particular how to deal with our debt and borrowing after Covid. I have never hidden away from those"
• "Once we have gripped inflation, I will get the tax burden down. It is a question of when, not if"

As a reminder, Conservative MPs need the support of at least 20 MPs by 18:00 to enter the first round of the ballot - Sunak's team say that's already in the bag.

In the first round of voting on Wednesday, candidates will need support from at least 30 MPs to go through.

More now from Nadine Dorries and Jacob Rees-Mogg's endorsement of Liz Truss outside Downing Street.

Culture Secretary Dorries says: "She has consistently argued for low tax policies and I'm particularly concerned about the 14 million people who voted for a [low-tax] manifesto and voted for a government."

And Rees-Mogg echoed Dorries' remark about Truss being a strong Brexiteer.

"She has been my strongest supporter in the cabinet in getting Brexit opportunities," he says.

"When we discussed taxation, Liz was always opposed to Rishi's higher taxes that again is proper conservatism.

"I think she's got the character to lead the party and the nation."

Chris Mason
Political editor

I'm at the Rishi Sunak launch event.

It is at the QE2 Conference Centre opposite Westminster Abbey.

Sunak’s slogan "Ready for Rishi" is on the big screen in the entrance hall.

This feels like the first big moment of this race.

How does he respond to the welter of criticism from his colleagues, seeking to demolish his record as chancellor?

What words does he choose, what demeanour or mood does he give off?

It's his first big test.

Jacob Rees-Mogg and Nadine Dorries have just given their backing to Liz Truss to succeed Boris Johnson as prime minister.

Speaking outside Number 10 Downing Street, the pair said Truss was a "bigger Brexiteer" than either of themselves.

Image source, Getty

As we've just reported, Rishi Sunak is launching his leadership campaign at 11:00. He's being supported by Norman Lamont - now Lord Lamont - who was chancellor from 1990 to 1993.

It's interesting that Lamont's endorsement repeats the line that it's not the time to cut taxes - this is a clear divide between Sunak and some of the other Conservative leadership candidates.