I'm not backing any Tory leadership contender, says Boris Johnson

Boris Johnson has refused to endorse any of the candidates running to replace him as Tory leader and PM.

Speaking for the first time since he announced last week that he was quitting, he said his successor should continue his own "great agenda".

Eleven candidates have come forward so far, most of them currently ministers in Mr Johnson's government.

Backbench Tory MPs are expected to set out the party's rules for the contest later on Monday.

Votes by Conservative MPs will narrow the field to two candidates by the time Parliament starts its summer break at the end of next week, with around 160,000 party members then having the final say over the next few months.

The candidates who have declared so far are:

Home Secretary Priti Patel is also believed to be weighing up whether to run.

The contender with the most declared supporters among MPs is currently Rishi Sunak, followed by Ms Mordaunt and then Mr Tugendhat.

Speaking at the Francis Crick Institute, a biomedical research facility in central London, Mr Johnson promised to spend his final weeks in Downing Street delivering "the programme we were elected on" in the Conservatives' landslide general victory of 2019.

He added that it was "not the job of the prime minister at this stage" to comment on a preferred successor.

"The job of the prime minister at this stage is to let the party decide, let them get on with it and to continue delivering on the projects that we were elected to deliver," Mr Johnson said.

"I know that whatever happens and whoever takes over, there is a great, great agenda to be continued."

Most of the candidates have focused on the issue of tax cuts during the early skirmishes of the contest.

Ms Truss, who announced on Monday that she was running, said she planned to slash corporation tax, reverse the recent National Insurance hike and reform business rates.

If elected she would take "immediate action" to assist with living costs, she wrote in the Daily Telegraph.

We don't yet know the rules of this race, or where the finish line is, but that's not holding anyone back.

So far, in short, we see the former chancellor Rishi Sunak leaping to the front when it comes to endorsements from fellow MPs.

And we see every other candidate, in one way or another, taking a potshot at him, particularly on the issue of tax.

The reason is this: by any modern comparison, tax and government spending is through the roof.

Plenty of Conservatives find this, well, un-Conservative.

And who's been chancellor for the last few years? Ah yes, Mr Sunak.

Read more from Chris here.

At the official launch of his campaign, Mr Javid said the Conservative Party had "lost its way", and promised to "make tough decisions in the national interest".

He promised to improve the UK's productivity, using tax cuts to "kick-start growth", while focusing on increasing social mobility and building more homes.

"We are not owed a prosperous future and we cannot just hope for it to arrive," Mr Javid added.

Interviewed on BBC Radio 4's Today programme, Mr Tugendhat said he would be "looking to lower taxes across every aspect of society", adding that he had been "one of a few Conservative MPs who didn't vote for the National Insurance rise", which he called a "tax on jobs".

Meanwhile, Mr Hunt told BBC Breakfast he would "get the British economy going", having served "at the coalface" by setting up his own business.

But he added that it would not be "moral" to do this by borrowing so much that the government was "loading up debts on future generations".

Chancellor Mr Zahawi pledged to cut the base rate of income tax if elected prime minister. Speaking at a Conservative Way Forward event, he said he would reduce it to 19p next year and 18p the following year.

However, Mr Sunak, who resigned as chancellor last week in protest at Mr Johnson's approach in office, has played down the prospect of tax cuts before public finances improve.

He warned against "comforting fairy tales" that would "leave our children worse-off tomorrow".

The 1922 Committee of backbench Conservative MPs meets later on Monday to set out the timetable for the leadership contest.

This comes amid calls from opposition parties and some Tory MPs for Mr Johnson to go immediately and appoint a caretaker prime minister in the meantime, with some suggesting his deputy Dominic Raab, who is not running for leader.

Committee vice-chair Nusrat Ghani told BBC Radio 4's World at One: "I do get contacted by colleagues from all sides of the party and there has been disquiet that we haven't had a situation where there was a caretaker prime minister in place.

"But I really do think that ship has sailed and I firmly think that, as the 1922, we just need to now focus on running a really smooth and efficient leadership election."

Labour leader Sir Keir Starmer criticised some of the Tory contenders over what he called "unfunded spending commitments" and an "arms race of fantasy economics".

He also attacked them for now opposing tax rises introduced by Mr Johnson and Mr Sunak, after voting for them previously.