Boris Johnson failed to turn up to his own press conference as noisy anti-Brexit protesters vented their anger, in extraordinary scenes in Luxembourg on Monday.

Xavier Bettel, the country’s leader, went ahead to speak to the press without the British prime minister – standing next to an empty podium as he fiercely criticised him.

Attacking the UK’s failure to present fresh proposals to break the Brexit impasse, Mr Bettel said – to applause from onlookers – that the “clock is ticking” and told Mr Johnson: “Stop speaking and act.”

Mr Johnson had been in Luxembourg to meet the country’s leader and Jean-Claude Juncker, the European Commission president, for the first time face-to-face.

But after enduring loud boos and taunts on the way in from assembled protesters, Mr Johnson walked away without doing his promised appearance in front of the media. A UK government source said he would instead do a clip in private with broadcasters away from the assembled public and press.

Addressing the irregularity, Mr Bettel told the assembled media: “Demonstrating is a right in democracy and it is also important to be able to exchange and listen to each other.” Asked about Mr Johnson’s openness to breaking the law to deliver Brexit, he added that such a move from the government “wouldn’t happen in Luxembourg”.

A Downing Street source said Mr Johnson had asked for the press conference to be moved inside away from the public, but that the request had been refused by Luxembourg’s government.

The source said Downing Street took the view that the PM would not be able to be heard properly above the protests. “What is the point of a press conference if the press cannot hear?” they said.

But Luxembourg government officials said there was no room inside large enough to move the press conference to. They added that Downing Street had suggested selecting just a few handpicked journalists to come inside – but the hosts rejected this on the basis that it would have been unfair.

Speaking to reporters without Mr Johnson, Mr Bettel suggested there had been no progress in the meeting, telling reporters: “I know that the UK government is unhappy with the withdrawal agreement as it stands.

“That’s why I thought it was important to speak to Prime Minister Johnson to get proposals. We need more than just words.”

An earlier meeting between Mr Johnson and Mr Juncker also ended without movement on the question of the Irish backstop. A European Commission spokesperson 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.”

Boris Johnson meets Jean-Claude Juncker (Getty)

The protesters who scared away Mr Johnson were mostly British nationals living in Luxembourg. About 200 people chanted loudly in the square outside the Luxembourg government headquarters, separated from the location of the press conference by a large iron fence and gate.

They held placards with slogans such as “Stop Brexit” and “We are not your bargaining chips” – a reference to comments by British government ministers. While they waited for Mr Johnson they listened to the EU anthem Ode to Joy played from a portable speaker system and chanted “stop the coup”.

Mr Johnson said in a private clip to broadcasters later: “I don’t think it would have been fair to the prime minister of Luxembourg [to attend]. I think there was clearly going to be a lot of noise and points might have been drowned out.”

However, the protesters were quiet for Mr Bettel, and in fact cheered him when he came out.

Mr Johnson was immediately criticised by opposition politicians for the decision to skip the press conference.

Labour MP Ian Murray told The Independent: “Boris Johnson is proving to be such a liar that he probably promised himself to turn up to the press conference. It just shows that he has nothing to say so avoids the scrutiny.

“He can’t provide any answers to his empty promises so decides to hide. Chicken promises from a chicken PM.”

The prime minister has faced many anti-Brexit protesters at a number of public appearances around the UK in the past few weeks – comically dubbed by critics as a “boos cruise”.

Tom Brake, the Lib Dems’ Brexit spokesperson, accused Mr Johnson of embarrassing the country in front of Luxembourg.

Protesters take to streets after Boris Johnson suspends parliament Show all 11 1 /11 Protesters take to streets after Boris Johnson suspends parliament Protesters take to streets after Boris Johnson suspends parliament Anti Brexit protesters march on Whitehall EPA Protesters take to streets after Boris Johnson suspends parliament Many of the protesters carried placards AP Protesters take to streets after Boris Johnson suspends parliament A demonstrator wears a Boris Johnson mask during a London rally AFP/Getty Images Protesters take to streets after Boris Johnson suspends parliament An anti-Brexit demonstrator wields an EU flag during a London rally. AFP/Getty Images Protesters take to streets after Boris Johnson suspends parliament The protesters also marched to Trafalgar Square, where they blocked traffic AP Protesters take to streets after Boris Johnson suspends parliament John McDonnell addressed crowds in Whitehall. PA Protesters take to streets after Boris Johnson suspends parliament A small group of Brexit supporters attempted to stage a counter protest in central London. AP Protesters take to streets after Boris Johnson suspends parliament Three people were arrested in London, including a woman who sat on the road near Trafalgar Square. AP Protesters take to streets after Boris Johnson suspends parliament In Oxford, locals and students gathered outside Balliol College, Boris Johnson's alma mater, to protest. PA Protesters take to streets after Boris Johnson suspends parliament Thousands of people gather in central Glasgow to protest against the prime minister. AFP/Getty Images Protesters take to streets after Boris Johnson suspends parliament Jeremy Corbyn spoke to protesters in central Glasgow. Getty

“It is clear Boris Johnson’s bluster and bravado from this morning is now revealed to be nothing more than hot air,” he said.

“Boris Johnson has no answers to the backstop and no intention of getting a deal. He is determined to drag us out of the EU, whatever the cost, and his disingenuous pretence otherwise is being revealed for all to see.

“The image of the empty podium in front of the Union Jack says it all – Boris Johnson is embarrassing Britain on the world stage.”

But Conservative MPs dismissed Mr Bettel’s decision to conduct the press conference without the prime minister as a stunt.

Tory MP David Morris said: “The PM and his team are working day in and day out to deliver a deal for Britain – this is no time for childish stunts.”

Nigel Evans, joint secretary of the 1922 Committee of Tory backbenchers, tweeted: “Pathetic grandstanding by Lux PM – another reason why the British people voted the way we did.

“We will not be humiliated in this way – well done Boris .... you should be ashamed of your PM Luxembourg.”

The trip to Luxembourg is part of a wider series of visits by Mr Johnson to European capitals in which the prime minister is trying to drum up support for dumping the Irish backstop from the Brexit deal.