Boris Johnson was 'empty chaired' at a humiliating EU press conference amid noisy protests following his meeting with Brussels chiefs in Luxembourg.
Protesters cheered and applauded as Luxembourg's PM Xavier Bettel challenged the absent Johnson over the UK's failure to produce practical solutions to the Irish border.
Earlier, Johnson's motorcade was forced to crawl away from the PM's meeting with Jean-Claude Juncker, amid a hail of boos from protesters lining the narrow streets of Luxembourg.
And Johnson abruptly withdrew from a planned outdoor press conference as noise from the angry protests grew nearby.
Speaking next to an empty podium at the press conference, Mr Bettel said: "Our people need to know what is going to happen to them in six weeks' time. They need clarity, they need certainty, and they need stability.
"You can't hold their future hostage for party political gains."
After Johnson's first face-to-face talks with the European Commission president, Brussels stepped up its demands for Britain to come forward with practical plans for the Northern Ireland border.
While Mr Juncker said the talks were "friendly" and negotiations will proceed "at high speed", there was little public sign of a breakthrough.
The commission said the Government had still not made "legally operational solutions" to replace the controversial Irish backstop element of the Brexit divorce deal, which keeps the UK closely tied to EU rules in order to avoid a hard border.
A European Commission statement released following the working lunch at Luxembourg City's Le Bouquet Garni restaurant said: "President Juncker recalled that it is the UK's responsibility to come forward with legally operational solutions that are compatible with the Withdrawal Agreement.
"President Juncker underlined the Commission's continued willingness and openness to examine whether such proposals meet the objectives of the backstop. Such proposals have not yet been made."
Both Brexit Secretary Steve Barclay and the EU's chief negotiator Michel Barnier were at the lunchtime meeting with the Prime Minister and commission president.
Downing Street said the meeting was "constructive" and contact between the two sides would be stepped up.
A Downing Street spokeswoman said: "The Prime Minister reconfirmed his commitment to the Good Friday/Belfast Agreement and his determination to reach a deal with the backstop removed, that UK parliamentarians could support.
"The Prime Minister also reiterated that he would not request an extension and would take the UK out of the EU on October 31.
"The leaders agreed that the discussions needed to intensify and that meetings would soon take place on a daily basis.
"It was agreed that talks should also take place at a political level between Michel Barnier and the Brexit Secretary, and conversations would also continue between president Juncker and the Prime Minister."
