RISHI Sunak will become the youngest prime minister in the modern era after his rival Penny Mordaunt pulled out of the Tory leadership contest.

Mr Sunak is now the only remaining candidate in the race to replace Liz Truss in Downing Street, having lost out to her in the last contest last month.

He will now become prime minister and Conservative leader without Tory members needing to vote.

Ms Mordaunt pulled out of the race moments before the announcement.

Mordaunt has conceded the Tory leadership race to Rishi Sunak and said he has her “full support”.

In a statement posted on Twitter, Ms Mordaunt said: “Our Party is our membership. Whether we are elected representatives, activists, fundraisers or supporters. We all have a stake in who our leader is.

“These are unprecedented times. Despite the compressed timetable for the leadership contest it is clear that colleagues feel we need certainty today. They have taken this decision in good faith for the good of the country.

“Members should know that this proposition has been fairly and thoroughly tested by the agreed 1922 process.

“As a result, we have now chosen our next Prime Minister. This decision is an historic one and shows, once again, the diversity and talent of our party. Rishi has my full support.

“I am proud of the campaign we ran and grateful to all those, across all sides of our party, who gave me their backing.

“We all owe it to the country, to each other and to Rishi to unite and work together for the good of the nation. There is much work to be done.”

Sir Graham Brady, chairman of the Tory backbench 1922 Committee, said there had only been one nomination, for Mr Sunak, received. 

Mr Sunak could become the new prime minister as early as today, although reports suggest it could happen tomorrow. 

The former chancellor was dealt a boost last night when Boris Johnson ended his bid for a dramatic comeback – leaving Mr Sunak in pole position, with Ms Mordaunt struggling to tally up the support of 100 Tory MPs needed to get on the ballot.

This morning, senior voices within the Conservatives including former party leader Iain Duncan Smith and ex-Tory chancellor Geoerge Osborne called on Ms Mordaunt to pull out of the leadership contest.

Earlier, Ms Mordaunt’s campaign has claimed she has received the support of 90 Tory MPs, and has urged others to back her so the party membership can select the next prime minister.

A campaign source said: “We have now passed 90. For the sake of the party, it’s important our members have their say.”

But as the 2pm deadline for nominations was reached, it has emerged that Ms Mordaunt did not have enough support from colleagues to force her way onto the ballot.

Some of her most enthusiastic backers switched to supporting Mr Sunak and urged her to withdraw.

Former minister George Freeman tweeted: “Penny Mordaunt is a huge force for Conservatism; with the life-story, vision and courage to help lead a Conservative revival. I’m proud to support her.

“But given the urgent need for Conservative stability and unity this week, I’m urging her to join and back Rishi Sunak today.”

Mr Sunak will be the UK’s first Hindu prime minister, the first of Asian heritage, and the youngest for more than 200 years at the age of 42.