Theresa May today slapped down Boris Johnson after he made an audacious pitch for her job in a fiery resignation speech in the Commons.
The former Foreign Secretary launched an excoriating attack on the PM's 'dithering' Brexit strategy in his first Commons speech since quitting.
He exploded back into the political fray by lambasting her 'miserable' strategy as the Prime Minister struggles to contain open warfare in the Tory party.
He complained that a 'fog of self doubt' had descended on the government after Mrs May's landmark Lancaster House speech on Brexit last year, and she had allowed negotiations with the EU to be dictated by questions about the Irish border.
But asked about the tongue-lashing Mr Johnson had given her in Parliament, Mrs May said she is too busy getting on with running the country to watch his speech.
In a devastating assault, Mr Johnson accused the PM of misleading voters about her intentions and putting the UK 'in limbo' with the Chequers plan she forced through Cabinet.
Making a clear pitch for the top job without directly calling for Mrs May to quit, he added: 'It is not too late to save Brexit.'
The searing assessment - hailed as the 'speech of a statesman' by Jacob Rees-Mogg - could throw Mrs May back into turmoil just as she was hoping to limp into the summer parliamentary break.
Mrs May was not in the chamber for Mr Johnson's statement, as she was struggling to defend her Chequers plan in a stormy encounter with senior MPs on the Liaison Committee on another part of the estate.
She also faced a showdown with restive Tory backbenchers at a private end-of-term meeting tonight pleading with them to 'take the fight to Labour' rather than squabbling among themselves. Extraordinarily, Mrs May was kept waiting by the 1922 committee outside the room where the gathering is held - leaving her at the mercy of lurking journalists.
Asked whether she would be watching Mr Johnson's speech later, she said: 'I think I'll probably be doing my red box.'
She also shrugged off questions about whether she would survive the summer as leader. 'I think you know the answer to that,' she said. 'We all need a break.'
Mr Johnson triggered chaos in the government on Monday last week when he resigned days after the summit at the PM's country residence.
Allies of the premier have been braced for him to make a bid to oust her - although sources close to the MP have stressed he will not make a 'personal' assault.
Mr Johnson was flanked by former aide Conor Burns on the famous green benches, as well as Brexiteers Nadine Dorries and Ben Bradley.
David Davis, who also resigned last week, was also nearby.
He positioned himself in the almost exactly the same spot where Geoffrey Howe delivered his 1990 resignation speech that dealt a killer blow to Margaret Thatcher.
Mr Johnson was flanked by key Brexiteers on the famous green benches, including Iain Duncan Smith, Edward Leigh, Conor Burns, Nadine Dorries and Ben Bradley.
David Davis, who also resigned last week, was also nearby.
Letting loose on the PM's whole approach with a series of carefully calibrated but damning salvos, Mr Johnson said she must heed anger from Eurosceptics.
'The result of accepting the EU's rule books and of our proposals for a fantastical 'Heath Robinson' customs arrangement is that we have much less scope for trade agreements,' he said.
Mr Johnson accused the PM of 'saying one thing to the EU.. and another thing to the electorate'.
'It's not too late to save Brexit. We have changed tack once in these negotiations, and we can change tack again.'
In a rallying cry to Eurosceptics, Mr Johnson said that Mrs May had not even attempted to take a tough line with the EU.
'We never actually turned that vision into a negotiating position in Brussels and we never made it into a negotiating offer.
'Instead we dithered and we burned through our negotiating capital. We agreed to hand over a £40billion exit fee with no discussion of our future economic relationship.'
He said despite what some former Cabinet colleagues thought it was not possible to do a 'botched treaty now' and then 'break and reset the bone later on'.
'We haven't even tried. We must try now because we will not get another chance to get it right,' Mr Johnson added.
Mr Johnson said the Chequers deal would leave Britain in 'limbo' and the government must 'believe' in the country.
He told the Commons: 'We are volunteering for economic vassalage.'
Mr Johnson insisted that checks away from the Northern Irish border and technical solutions were possible.
He cited concerns raised by himself and former Brexit secretary David Davis, saying: 'When I and other colleagues... proposed further technical solutions to make customs and regulatory checks remotely, those proposals were never properly examined, as if such solutions had become intellectually undesirable in the context of the argument.'
Mr Johnson said: 'We need to take one decision now before all others and that is to believe in this country and what it can do.'
Mr Johnson said it became 'taboo to even discuss technical fixes' regarding the Irish border.
He added: 'After 18 months of stealthy retreat we have come from the bright certainties of Lancaster House to the Chequers agreement.'
Mr Johnson said Britain should be 'great independent actors' on the world stage, not 'rule takers'.
'That was the vision of Brexit that we fought for,' he said.
'That was the vision that the Prime Minister rightly described last year.
'That is the prize that is still attainable. There is time. And, if the Prime Minister can fix that vision once again before us, then I believe she can deliver a great Brexit for Britain with a positive, self-confident approach that will unite this party, unite this House and unite this country as well.'
Earlier, Mrs May was goaded at PMQs by Conservative backbencher Andrea Jenkyns who demanded to know when she had decided that 'Brexit means Remain'.
But amid jeers in the Commons a clearly frustrated Mrs May hit back that she was still committed to leaving the EU and wanted a 'workable' solution.
The clashes, at a raucous last questions session before the summer recess, came after Mrs May narrowly fended off a potentially existential challenge to her negotiating strategy last night.
Amid dramatic scenes at Westminster last night, a dozen Conservative Remainers defied warnings they would collapse the Government by siding with Jeremy Corbyn to demand Britain stays in the EU customs union.
Mrs May has repeatedly insisted that the UK must not be in a customs union, as it would prevent trade deals being struck elsewhere.
But rebels ignored warnings from Tory chief whip Julian Smith that defeat would prompt him to call a vote of confidence in Mrs May today, followed by a possible general election.
Tory insiders said another ten Eurosceptic MPs would have sent in letters of no confidence in Mrs May if she had lost last night's vote - potentially pushing the total over the 48 needed to spark a leadership challenge.
Rebels inflicted an early defeat on the Government when they voted to keep Britain tied into the European Medicines Agency after Brexit by 305 votes to 301.
But, minutes later, the tables were reversed as MPs voted by 307 to 301 to reject an amendment to the Trade Bill ordering the PM to pursue a continuation of the customs union.
Five Labour MPs voted with the Government: former ministers Frank Field and Kate Hoey and backbenchers John Mann, Graham Stringer and Kelvin Hopkins, who is currently sitting as an independent following suspension. If they had voted the other way, the Government would have lost by four votes.
Attacking her leader at PMQs, Ms Jenkyns - who has already urged Mrs May to quit - asked: 'Could the Prime Minister inform the House at what point it was decided that Brexit means Remain?'
Mrs May insisted that her mantra of 'Brexit means Brexit' still stood.
'At absolutely no point, because Brexit continues to mean Brexit,' she replied.
'And if I can say to her, I know she wants us to talk about the positives of Brexit and I agree with her.
'We should be talking about the positive future for this country. I understand she's also criticised me for looking for a solution that is workable.
Theresa May today repeated her warning that 'no deal is better than a bad deal' - as she admitted that some of her Brexit plan might not be ready in time.
The Prime Minister tried to fend off claims that her controversial Brexit proposal is 'baffling' - but she struggled to explain how her customs plans would actually work.
And she revealed her plans for the EU to collect tariffs for the UK and vice versa might not be ready before the UK fully leaves the bloc, after the transition period, in December 2020.
Mrs May made the admission as she was grilled by senior MPs sitting on the Liaison Committee amid a Tory civil war over her Chequers plans - which are also known as the facilitated customs arrangement
The PM told the hostile committee that 'no deal is better than a bad deal' and that 'preparations for a no deal are being stepped up'.
Her comments came after her International Trade Secretary Liam Fox warned that EU countries could see their GDP - their national income - fall by as much as 8 per cent.
Mrs May told the committee: 'The majority of what is required for this facilitated customs arrangement will definitely - as we have indicated - be in place by December 2020.
'There is a question as to the speed with which the repayment mechanism would be in place.
'So far the suggestion is that could take longer to be put into place. That has yet to be finally determined.'
This article has been adapted from its original source.
© Associated Newspapers Ltd.