Scrapping of backstop is only way I'll do deal with Europe, says PM Johnson
But Brussels is adamant that there will be no renegotiation
Boris Johnson has made ditching the Irish backstop a red line for new Brexit negotiations, telling MPs that he will talk with Brussels only on that basis.
His position comes despite EU officials repeatedly insisting they will not reopen the withdrawal agreement sealed with Theresa May last November, of which the backstop forms an integral part.
Making his first statement to the House of Commons as Prime Minister, Mr Johnson restated his absolute commitment to taking the UK out of the EU by October 31, with or without a deal.
And he insisted that any deal must strip out all mention of the backstop - which keeps the UK in a customs union until an alternative way is found to keep the Irish border open - and hold the issue back to later negotiations on the future trade relationship between the UK and EU.
Despite having voted in favour of Ms May's deal less than four months ago, the new PM denounced it as "unacceptable" and insisted that "no country that values its independence and indeed its self-respect" could agree it.
A time limit on the backstop - something which has already been rejected by the EU - was "not enough", he said.
"If an agreement is to be reached it must be clearly understood that the way to the deal goes by way of the abolition of the backstop," Mr Johnson told MPs.
"For our part we are ready to negotiate in good faith an alternative, with provisions to ensure that the Irish border issues are dealt with where they should always have been: in the negotiations on the future agreement between the UK and the EU."
To heckles of "How?" from Opposition MPs, Mr Johnson insisted that alternative arrangements for overseeing movements across what would be the post-Brexit UK's only land border with the EU were "perfectly possible and perfectly compatible with the Belfast, or Good Friday, Agreement".
He said that he and Brexit Secretary Dominic Raab were "ready to meet and to talk on this basis to the Commission or other EU colleagues whenever - and wherever - they are ready to do so".
Brussels responded swiftly, with European Commission president Jean-Claude Juncker using his first phone call with the new Prime Minister to say the existing withdrawal agreement was "the best and only" deal possible.
Mr Johnson said the Government was "turbo-charging" preparations for a no-deal break on October 31 if the EU refused to engage.
In Brussels, the EU's chief negotiator Michel Barnier said Mr Johnson's demands were "unacceptable" and accused him of using "combative" language to put pressure on the remaining EU27.
A European Commission spokesman said Mr Juncker "listened to what Prime Minister Johnson had to say, reiterating the EU's position that the withdrawal agreement is the best and only agreement possible".
He said he would be prepared to "analyse any ideas put forward by the United Kingdom, providing they are compatible with the withdrawal agreement".
The two politicians exchanged mobile phone numbers and agreed to remain in touch "should the United Kingdom wish to hold talks and clarify its position in more detail".
Downing Street said Mr Johnson told Mr Juncker "if an agreement is to be reached it must be understood that the way to a deal goes by way of the abolition of the backstop" - the measures aimed at keeping the Irish border open in all circumstances.
Mr Johnson appeared in the Commons chamber to cheers from Tory MPs still reeling after his brutal purge of Theresa May's Cabinet which saw 17 ministers sacked or quit their jobs.
He underlined his determination to take Britain out of the EU by the end of October, warning that failure to do so would lead to a "catastrophic loss of confidence" in the political system.
Despite the fears of many MPs that he is setting the country on course for a no-deal break, Mr Johnson insisted he would still prefer to leave with a new agreement in place.
However, he said Mrs May's withdrawal agreement - rejected three times by MPs - was "unacceptable" and that the Northern Ireland backstop had to go.
The comments from Brussels echoed Taoiseach Leo Varadkar, who said Mr Johnson's claims he could get a new deal by October 31 were "not in the real world".
Mr Johnson, who earlier chaired the first meeting of his new Cabinet, insisted the UK side was ready to meet and talk with the EU "whenever they are ready to do so".
"I would prefer us to leave the EU with a deal," he said.
"I would much prefer it. I believe that is still possible even at this late stage and I will work flat out to make it happen.
"For our part, we will throw ourselves into these negotiations with the greatest energy and determination and in the spirit of friendship.
"And I hope that the EU will be equally ready and that they will rethink their current refusal to make any changes to the withdrawal agreement."