Boris Johnson has refused to rule out a leadership challenge to British Prime Minister Theresa May as he took another swipe at her Chequers plan ahead of the Conservative Party Conference.
The former foreign secretary said the Mrs May was "a remarkable person" who will "go on for as long as she feels it necessary" in an interview with BBC News.
It came after he used a 4,500-word newspaper column to issue a blistering attack on her Brexit strategy ahead of the party's annual gathering, which starts in Birmingham on Sunday.
Mr Johnson also refused to rule out voting against a deal based on Chequers in parliament even if it meant bringing down the government, when asked repeatedly by the BBC.
And he made a thinly-veiled jibe at Michael Gove, saying the idea of settling for a Chequers-type deal now that could be altered later - as suggested last week by the Environment Secretary - was "complete pie in the sky".
Mr Johnson, who is due to give a speech to conference on Tuesday - the day before Mrs May's keynote address - was asked repeatedly by the BBC to rule out running against her.
He said: "The Prime Minister will go on, as she 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 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."
In a separate interview with Sky Mr Johnson had said that, despite the EU formally rejecting Chequers, it would be a "great deal for them".
He went on: "I just want to make clear because I don't think people quite get this - the Chequers deal, were it to be agreed with the EU, would be a political triumph for Brussels."
Mr Johnson had used an op-ed in the Telegraph newspaper to accuse the British government and civil service of a "pretty invertebrate performance" in negotiations and said there had been "a collapse of will by the British establishment to deliver on the mandate of the people".
The former foreign secretary, who sensationally quit the cabinet in July, described the Chequers plan as "a moral and intellectual humiliation for this country" that will "cheat the electorate" if implemented.
As a priority, the former London mayor urged the government to ditch Chequers and negotiate a Canada-style free deal which would "fulfill the instruction of the people".
Mr Johnson also argued for a new withdrawal agreement which states that the Irish border question will be settled as part of the deal on the future economic arrangements.
Number 10 hit back at his proposal for a "Super Canada" trade deal, with a source pointing out Mr Johnson had been part of the committee which agreed the need for a customs backstop in Northern Ireland.
Brexit minister Chris Heaton-Harris added: "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."
Asked by the BBC whether he would vote against it in Parliament even if it would bring down the government, Mr Johnson said "we will have to see. At the moment, I cannot see how I can support Chequers".
He added: "I think that at least some of my colleagues round the Cabinet table are seeing that Chequers is no way forward for a great economy like the UK. It's simply intolerable.
"We cannot submit to that kind of arrangement. No other country would do it.
"There is a much much better way forward and I think we need to get back to it, and by the way I think that would command support across the House of Commons."