Boris Johnson fails to rule out challenging Theresa May leadership on eve of party conference

Boris Johnson has not ruled out challenging Theresa May for the Tory leadership ahead of the party’s annual conference.

The ex-foreign secretary was twice asked whether he would rule out launching a bid against the prime minister, but would not do so.

Instead he again warned the prime minister there is time for her to ditch her Chequers proposals for Brexit, having earlier in the day set out his own ideas in a sprawling newspaper article.

It comes just 24 hours before Conservatives begin gathering in Birmingham for what is to be one of the most fraught conferences in years.

Ms May has faced a flood of criticism in the past two days over her approach to Brexit, but also from MPs crying out for a more substantial domestic agenda, in the wake of Jeremy Corbyn’s well received conference speech in Liverpool.

Speaking to the BBC News’s Laura Kuenssberg, Mr Johnson was asked to rule out challenging the prime minister.

He said: “My job is to speak up for what I believe in and the vision that I’ve set out today and I believe in it very, very sincerely and you know, I’m going to keep going for as long as it takes.”

Pressed again he said: “The prime minister will go on. As she said to us herself, and as she said to the country. She’s a remarkable person, she will go on for as long as, as she feels it necessary.

“But the most important thing for me is to avert what I think would be a political and economic disaster for this country, which is to agree to come out of the EU but still to be run by the EU. What is the point of that, what will we have done?

“And I think there is still time for her to change course.”

Mr Johnson also used the interview to set out again his own support for a Canada-style trade deal with additional elements as an alternative to the plans set out by Ms May.

He also undertook other broadcast interviews indicating that he intends to use a high-profile media approach to pressuring Ms May throughout the conference season.

Earlier in the day he wrote an article for the Daily Telegraph in which he indicated that the prime minister’s proposals would result in a national “humiliation” for Britain.

He said in the BBC interview: “I did play a role in the Leave campaign and we had a very clear vision for what could be achieved and I believe in it, absolutely, passionately.

“And the sad thing for me is that although I spent two years in government wrestling with, as it were, the steering wheel, to try to keep us on the right track, in the end it wasn’t possible, and by Chequers it became clear that we were effectively going to stay, both in the customs union and to be rules takers.

“So my duty now is to make the case for freedom again.”

He argued that the issue of the Irish border, which has proved such a stumbling block to negotiations in Brussels, could be solved, but that the plans supported by the EU should not be countenanced.

Mr Johnson was in the cabinet last December when Ms May’s administration agreed the “joint report” with Brussels that committed the UK to a “backstop” arrangement, that could keep Northern Ireland or even the whole UK in the customs union – though Ms May has since said she wants an alternative arrangement.

He also insisted that as part of a free trade deal, instead of the Chequers proposals, the EU would agree to an arrangement that allowed free flow of goods across the border and for checks to take place away from the frontier.

But Brexit minister Chris Heaton-Harris hit back saying: “This is not a workable or negotiable plan for Brexit – as both sides have made clear on several occasions, no deal is available without a guarantee that there would be no hard border in Northern Ireland in any eventuality, the so-called Irish backstop.

“The government is united behind the prime minister’s efforts to negotiate a good deal that works in the interests of the whole United Kingdom.”

Speculation about the timing of a Johnson leadership bid has ramped up in recent months with the former cabinet minister using his newspaper columns to launch weekly attacks on the PM’s plans.

He will also be speaking at a Brexit rally in Birmingham on Tuesday and at meetings in the conference fringe likely to be well attended by pro-Brexit party members.

A government source said of his article on Friday: “Boris was a member of the cabinet that agreed the December joint report – and praised the PM for doing so – and was part of the committee that agreed the customs backstop.

“The truth is that reneging on those two things would simply guarantee no deal.

“So this is just another very lengthy article which doesn’t offer any answers; rather, it regurgitates ideas which would damage our union of nations and put jobs at risk.”