Theresa May has said “important progress” on Brexit was made at last week’s EU summit – but Jeremy Corbyn said it sounded like “Groundhog Day”.
The PM said she had a “degree of confidence” of making enough progress by December to begin trade talks.
She also said there would be no “physical infrastructure” on the border in Northern Ireland.
Meanwhile, the EU Commission president dismissed a German newspaper’s account of his dinner with the PM.
“Nothing is true in all of this,” Jean-Claude Juncker said, rejecting the article’s claims Mrs May “begged for help” when they met and seemed tired and politically weak.
After five rounds of UK-EU talks, there has been no breakthrough in the first phase of negotiations between the UK and the EU.
At the summit, the other 27 EU leaders decided progress on the Brexit separation issues had not been “sufficient” to open talks on future trade relations with the UK yet – but they did agree to discuss future arrangements amongst themselves, paving the way for talks with the UK to possibly begin in December.
Businesses are calling for urgent agreement in setting up temporary transition arrangements after the UK’s departure date in March 2019.
But some pro-EU MPs expressed concern that the UK could leave without one in place, after Mrs May suggested it was dependent on details of the final “partnership” being clear.
“The point of the implementation period is to put in place the practical changes necessary to move to the future partnership,” she said as she updated MPs on last week’s summit.
“In order to have that, you need to know what the future partnership is going to be.”
Mrs May also said the question of citizens’ rights after Brexit remained her “first priority”, with a deal within “touching distance”, and pledged that EU nationals living in the UK would not face “bureaucratic hurdles” after March 2019.
Her “clear commitments” on another sticking point, the UK’s financial settlement, had helped moved talks forward, she said.
In response, Mr Corbyn compared Mrs May’s updates to 1993 comedy Groundhog Day, where the lead character played by Bill Murray lives the same day over and over again.
“Well, here we are again after another round of talks,” he said, saying it was “no clearer” when future talks would begin or what the UK had agreed to so far.
Talks have reached an “impasse” with no progress abroad or at home, he said, adding that the citizens’ rights issue “could have been dealt with 16 months ago”.
Just before the PM got to her feet in the Commons, European Commission President Jean-Claude Juncker denied leaking an unsourced account of his dinner with the PM published in German newspaper Frankfurter Allgemeine.
The account, largely written from the perspective of EU officials, suggested Mrs May appeared “anxious, despondent and disheartened” and had spoken of her limited room for manoeuvre back at home.
“Everyone can see: the prime minister is marked by the struggle with her own party,” the article stated, according to a translated version quoted by a number of British newspapers.
“She has deep rings under her eyes. She looks like someone who doesn’t sleep at night.”
But asked by the BBC if he had spoken to the German press, Mr Juncker said: “No, never. I am really surprised – if not shocked – about what has been written in the German press.
“And of course repeated by the British press. Nothing is true in all of this.
“I had an excellent working dinner with Theresa May. She was in good shape, she was not tired, she was fighting, as is her duty, so everything for me was OK.”
In the Commons, Tory MP Bernard Jenkin said anyone suggesting Mrs May was weak “seriously underestimates” the PM and the Conservative Party, urging her to “stick to her guns”.
The apparent leak of what happened at the dinner follows a similar incident in April, when Mrs May accused some in the EU of “meddling” in the general election campaign after details of a dinner between her and Mr Juncker in Downing Street appeared in the German press.
Downing Street said it had no comment on the latest reports and pointed out that both sides were of the view that the recent get-together had been “constructive and friendly”.
Earlier Nick Timothy, who was the PM’s chief of staff until he quit after the general election, suggested the disclosure had all the hallmarks of coming from the European Commission.
In a reference to EU official Martin Selmayr, he tweeted: “After constructive Council meeting, Selmayr does this. Reminder that some in Brussels want no deal or a punitive one.”
But Mr Selmayr said the claim was “false” and neither he nor Mr Juncker had any “interest in weakening” Mrs May.
He tweeted: “I deny that 1: we leaked this; 2: Juncker ever said this; 3: we are punitive on Brexit. It’s an attempt 2 frame EU side & 2 undermine talks.”
The European Commission said it was working for a fair Brexit deal and had “no time for gossip”.
“Some people like to point at us to serve their own political priorities,” a spokesman said.
“We would appreciate if these people would leave us alone.”