Protesters wielding pro-democracy placards and EU flags rallied on Saturday in dozens of British cities against Prime Minister Boris Johnson's controversial move to suspend

parliament just weeks before Brexit.

In the biggest demonstration, thousands of whistle-blowing, drum-banging people gathered raucously outside the gates of Downing Street in London chanting "Boris Johnson shame on you!"

"I'm absolutely disgusted by what's happening here," said attendee Maya Dunn, 66, a Dutch citizen living in Britain, who accused Johnson of "riding roughshod over everybody".

"You just can't trust him," she said.

The demonstrations come ahead of an intense political week in which Johnson's opponents will go to court to block his move to suspend parliament from mid-September and legislate against leaving the European Union without an agreement.

Johnson, who only came to power in July following a Conservative Party leadership election, hit out at the prospect in a newspaper interview published Sunday.

"What on earth are we achieving by this?" he told the Sunday Times, noting Brexit had already been delayed twice this year and warning rebel Tory MPs risked toppling the ruling Conservatives.

"What we need to do is get a deal done, or if we can't get a deal done then get out of the EU on October the 31st, come what may.

"And that's what we're going to do," he added.

However the EU's chief Brexit negotiator said Brussels would not change the divorce deal struck with his predecessor Theresa May.

"I am not optimistic about avoiding a 'no deal' scenario," Michel Barnier wrote in the Sunday Telegraph newspaper.

- 'Wake up UK!' -

Johnson's parliament suspension was widely seen as a way of limiting the time his opponents have to organise against him.

In London, participants heard speeches from opposition politicians on a stage erected on Whitehall before marching through Westminster. Some held hand-written signs reading "Defend democracy: resist the parliament shutdown" and "Wake up UK! Or welcome to Germany 1933".

Organisers using the slogan #StopTheCoup claimed as many as 100,000 people turned out in London.

Some protesters blocked traffic, and the Metropolitan Police said it made three arrests at the event.

Crowds gathered in cities all over Britain, from Exeter in the southwest and Oxford in central England, to Manchester, York and Newcastle in the country's north.

They also rallied in Glasgow and Edinburgh in Scotland and in the Northern Irish capital Belfast.

"Nobody voted for a dictatorship," said Bridie Walton, 55, in Exeter, who added that Brexit had prompted her to demonstrate for the first time in her life.

"These are the actions of a man who is afraid his arguments will not stand scrutiny."

- 'Last chance' -

Jeremy Corbyn, leader of the main opposition Labour Party, has threatened to hold a no-confidence vote in the government -- which has a parliamentary majority of just one -- if MPs fail to pass a law to prevent a no-deal Brexit.

He said Saturday that next week is lawmakers' "last chance" to act.

"We will do absolutely everything we can to prevent a no-deal Brexit," Corbyn vowed during a three-day visit to Scotland.

Johnson has said he is ready to strike a deal as long as provisions for Britain to stay in the EU's crucial customs union even after Brexit are axed from the existing accord.

Despite Barnier's comments, Britain has said it is stepping up talks with the bloc in the coming weeks and Johnson's Brexit adviser David Frost is expected in Brussels next week.

The government meanwhile is ramping up preparations in case of no-deal.

- 'Lasting damage' -

Queen Elizabeth II gave her approval to Johnson's decision to suspend parliament for mid-September until October 14 on Wednesday, sparking widespread outrage, legal challenges and promises of resistance from parliamentarians.

Finance Minister Sajid Javid on Saturday defended the move, despite saying during the recent Tory leadership contest when he stood against Johnson that "you don't deliver democracy by trashing democracy".

"It doesn't usually sit for some time in September and early October," he told BBC radio, referring to parliament.

An online petition calling for the government to reverse its suspension has garnered nearly 1.7 million signatures.

In the courts, a Scottish judge is expected to hear a legal challenge against the suspension on Tuesday -- the same day MPs return from their summer break for their shortened parliamentary session.

There will be a separate court hearing Thursday for another challenge that is being supported by John Major, a former Conservative prime minister and staunch opponent of Brexit. afp