Rishi Sunak remained tight-lipped when leaving his office in London earlier, continuing to steer clear of commenting on the leadership contest.

Momentum has been growing behind the former chancellor's campaign this morning, with several former and current ministers among the 185 MPs who have publicly backed him.

Meanwhile, his rival Penny Mordaunt has been busy trying to bolster her current endorsement count, which is currently understood to be 26 MPs.

It's been reported her team have been busy overnight and today trying to get the pledges of Boris Johnson supporters, after he dropped out of the race yesterday.

Mordaunt is less tight-lipped - tweeting seven times already, external this morning.

On Monday morning, sterling stood around 0.4% higher, at $1.13, after Rishi Sunak emerged as the favourite to become the new prime minister.

Meanwhile, government borrowing costs dropped as the markets opened after the weekend.

You can read more about how the markets are reacting and why, here.

Many of you reading every twist and turn on this page have been sending in your comments this morning, as Rishi Sunak and Penny Mordaunt enter the final stretch of the Tory leadership contest before nominations close.

Here's some of what you've been saying:

Penny Mordaunt should pull out of the race to allow a "coronation" of Rishi Sunak as prime minister and bring unity to the party, a senior Conservative member of the House of Lords has said.

Michael Forsyth says "the pantomime" needs to end so the government can get on with its job.

He tells the BBC News Channel it is "perfectly obvious" Sunak has more support, adding:

Nick Eardley
Chief political correspondent

Reaching 50% support among Tory MPs is symbolically important for Rishi Sunak.

He can now say he has the backing of his party in parliament. If this goes to members, that could be an important factor.

There has been a flood of extra support for Sunak this morning. He has considerable momentum in parliament.

But Penny Mordaunt isn’t throwing the towel in just yet.

Image source, Reuters

There is "absolutely no chance" Penny Mordaunt will be stepping down from the race, one of her key backers says.

Andrea Leadsom, who ran for the Tory leadership against Theresa May in 2016 and pulled out before it went to a vote among Tory members, says it is "really important there is a contest" and the party must "give people a choice".

She says Mordaunt's campaign is "supremely confident" this morning and there is a "lot of support for Penny from colleagues".

Currently, Mordaunt has fewer than 30 public backers among Conservative MPs - with the rules for this edition of the leadership contest requiring 100 MPs by 14:00 BST today to qualify.

Sunak has more than 170.

She thinks many former Boris Johnson supporters will go to Mordaunt.

Since Boris Johnson pulled out of the race last night, we've been monitoring to whom Tory MPs previously supporting him will shift their endorsement.

Early moves late last night and early this morning suggest many MPs are backing former chancellor Rishi Sunak.

His Treasury successor Nadhim Zahawi, former home secretary Priti Patel and current Foreign Secretary James Cleverly have already shifted their vote.

Dozens of MPs who backed Johnson haven't publicly switched to one of the others yet - but we expect this to move fairly rapidly over the course of the morning.

We're also keeping an eye on whether Sunak's rival to take over as Tory leader, Penny Mordaunt, will pick up enough to hit the threshold of 100 backers (out of 355 total fellow MPs) needed by 14:00 BST today.

According to our tally, as of around 10:00 BST the numbers were:

Image source, .

Just joining us or need a re-cap? Here are the latest developments in the Tory leadership campaign.

• Rishi Sunak is the clear favourite to replace Liz Truss as UK prime minister
• Penny Mordaunt is still in the contest but currently has fewer than 30 supporters who have confirmed their backing publicly - that's below the 100 needed by 14:00 to send the contest to party members

• Despite lagging behind, Mordaunt's team say they are within “touching distance” of getting enough backers
• Boris Johnson withdrew from the race on Sunday night
• The former PM claimed to have reached 102 backers although fewer than 60 MPs had publicly declared their support for him
• High-profile MPs are switching allegiance from Johnson to Sunak, including former Home Secretary Priti Patel and cabinet ministers James Cleverly and Nadhim Zahawi
• Labour has reiterated its call for a general election instead, along with other parties not in power at Westminster

Hopeful contenders have until 14:00 BST today to gather the support of at least 100 MPs if they wish to have their name on the ballot for the leadership contest.

At the moment, former Chancellor Rishi Sunak has the most backers while Penny Mordaunt is racing to secure enough.

If they face, off a vote then goes out to Conservative party members to decide.

Professor Sir John Curtice, politics professor at Strathclyde University, tells BBC Radio 4's Today programme polling suggests Sunak is more popular now than he was in the summer leadership contest.

Then, some polls placed Mordaunt ahead of Sunak amongst the membership.

But more recently, a poll held just before Liz Truss resigned as PM last week, showed 23% of Tory members would back Sunak while 9% would back Mordaunt.

But he warns that poll included Boris Johnson, who has now stepped away. Where his backers go will have an impact.

According to the BBC's official tally, Sunak has the public support of 155 Tory MPs, while Mordaunt has the backing of 25.

Image source, Getty Images

Nadine Dorries says it is not "the end of Boris Johnson" after the former prime minister ruled himself out of the race for No 10.

The ex-cabinet minister said "hours of conversations" took place between Johnson, Rishi Sunak and Penny Mordaunt to agree on a unified solution, but the remaining candidates "declined to come together".

Johnson supporters are "very keen that we have unity in the party" and will be "very keen to back a candidate to make that happen", she told Times Radio.

Dorries, a staunch Johnson ally, suggested Mordaunt was not a serious contender.

"I don't think, when you're talking about Penny Mordaunt, you're asking anyone to step back. I mean, Penny hasn't really held a serious job in government.

"The fact that Penny asked Boris Johnson to step back for her, I thought was quite interesting."

The former PM stepped back "for the right reasons", Dorries said, insisting "that doesn't mean it's the end of Boris Johnson".

Labour has reiterated its call for a general election, calling the Tory leadership contest "completely undemocratic".

Shadow attorney general Emily Thornberry says the public is "really fed up" of the Tories deciding the prime minister among themselves.

"If we'd only had a general election after Boris Johnson had gone, we would have another government by now and wouldn't have had Liz Truss and our economy wouldn't have crashed in the way that it did," she told BBC Radio 4's Today programme.

Noor Nanji
Business reporter

Government borrowing costs fell on Monday morning, while the pound rose after Boris Johnson dropped out of the Conservative leadership contest.

The interest rate - or yield - on bonds due to be repaid in 30 years' time dropped to 3.9%, making government borrowing cheaper.

They had hit 5.17% on 28 September in the aftermath of the mini-budget when the then-Chancellor, Kwasi Kwarteng, set out one of the biggest tax cuts packages seen in decades but did not explain how they would be funded.

Meanwhile, the yield on bonds due to be repaid in five years' time, which underpins the cost of new five-year fixed rate mortgages, fell to 3.8%.

The pound has also gained against the dollar and is currently trading at $1.134.

Two former cabinet ministers have in the last few minutes called on Tory MPs to back Rishi Sunak to lead the party.

Former Home Secretary Priti Patel is the latest Boris Johnson supporter to endorse Sunak as Conservative Party leader, joining cabinet ministers James Cleverly and Nadhim Zahawi in switching allegiance in the last 12 hours.

Her endorsement was echoed by Michael Gove, whose leadership preference was undeclared until now.

Paul Goodman, editor of Tory news website Conservative Home, is advising Penny Mordaunt not to protract her Tory leadership campaign as her rival Rishi Sunak appears to be closing in on No 10.

Mordaunt currently has the support of at least 25 MPs, and could look to gain more Boris Johnson backers after he pulled out of the race last night.

"I have to say to Penny Mordaunt, for the good of the Conservative Party and the country, just don't push it because look at the figures," Goodman told BBC Radio 4's Today programme.

"Rishi Sunak, according to our count and other counts that are similar, has got 155 supporters - 179 is half the parliamentary party so he's really almost there."

He added that should Sunak succeed Liz Truss as prime minister, he will face "enormous problems", including the "disastrous legacy" left by his predecessor's brief administration.

"He's going to have to come to the Commons with his chancellor - I presume it will be Jeremy Hunt - with a whole programme of public spending cuts and tax rises just as a Labour government would now if it were there," Goodman added.

The Conservative Party is currently not fit to run the country and attract investment, according to a long-time supporter of the Tories.

Guy Hands, founder of the investment firm Terra Firma, says that unless Brexit is renegotiated, the UK economy is "frankly doomed".

He warned of increased taxes, reduced benefits, higher interest rates and "eventually a bailout from the IMF [International Monetary Fund]" unless the next leader of the party has the "intellectual capability and authority" to work out a revised Brexit deal.

Hands told BBC Radio 4's Today programme.

Nick Eardley
Chief political correspondent

Rishi Sunak and Penny Mordaunt will spend this morning trying to shore up support.

Both have tweeted their praise of Boris Johnson in an attempt to win over the MPs who had been backing him.

Team Mordaunt had been hoping they'd be able to hoover up a lot of Johnson's backers.

They believed she was their natural home last night. But at the moment, Rishi Sunak still has the momentum.

It's interesting that two prominent cabinet allies of Johnson - James Cleverly and Nadhim Zahawi - are now backing Sunak.

Other backbenchers have done the same. That suggests to me that Mordaunt is not picking up Johnson supporters en masse in the way she would have hoped.

That will make it harder (though not impossible) for her to get over the line.

Another Boris Johnson backer has switched to endorse Rishi Sunak for Tory Party leader - this time Foreign Secretary James Cleverly.

Cleverly announced his support for Johnson yesterday just hours before Johnson pulled out of the race.

He joins cabinet minister Nadhim Zahawi who also U-turned on his endorsement, external last night.

Image source, Getty Images

A Tory MP who backed Boris Johnson to lead the party says the party is now "ungovernable" and a vote on the next prime minister should be put to the nation.

Sir Christopher Chope says he's "very angry", adding that the former prime minister and his successor Liz Truss had their authority "undermined by the people who now wish to take over and inherit the crown".

"We now have the prospect of having a Conservative Party leader who doesn't have a mandate form the country and won't even have a mandate from the membership either," Chope told BBC Radio 4's Today programme.

"Respect is a mutual thing, if people who are now seeking the crown want to have the respect which comes from having a mandate then the best way they can get that respect is by winning a mandate with the people. That's why I think a general election is the only answer, otherwise we're just going to go from bad to worse."

He added: "The party is ungovernable in the House of Commons and so we're going to have continuing rebellions so I'm very pessimistic."

Boris Johnson's former communication director says the return of the former PM "would've been a disaster".

"In truth, and it pains me to say it because I've known him a long time, Boris has displayed a startling lack of self-awareness even by Boris’s own standards," Will Walden tells BBC Breakfast.

"To believe that after just six weeks out of power, having been booted out by the Tory party... with his personal ratings in the country absolutely tanking, that somehow people wanted him back I think was pretty hubristic.

"He wasn't the answer then, isn't the answer now, and I don't think he will be the answer in the future," he adds.