Queen Elizabeth attends an event in London. File

Britain's Queen Elizabeth has approved Prime Minister Boris Johnson's plan to suspend parliament, a statement from the official body of advisers to the Queen, known as the Privy Council, said on Wednesday.

The statement confirmed that parliament would be suspended on a day between Sept.9 and Sept.12, until Oct.14.

"It is this day ordered by Her Majesty in Council that the Parliament be prorogued on a day no earlier than Monday the 9th day of September and no later than Thursday the 12th day of September 2019 to Monday the 14th day of October 2019," the statement said.

Though Johnson previously had refused to rule out such a move, the timing of the decision took lawmakers — many of whom are on vacation — by surprise.

Cheered on by US President Donald Trump, Johnson launched his boldest move yet to take the country out of the European Union by Oct.31 with or without a divorce deal, by setting a new date for a state opening of parliament.

Known as the Queen's Speech, the formal event will be held on Oct.14 and be preceded by a suspension of the House of Commons, meaning parliament will not sit between mid-September and mid-October.

More than 500,000 people have signed a petition demanding that Johnson scrap his plan to suspend parliament ahead of Brexit.

A protester with a mask of Boris Johnson demonstrates outside Downing Street in London on Wednesday. AP

His move sparked anger among opposition lawmakers and Remain-supporting Conservatives, with former education secretary Justine Greening condemning it as a “grubby attempt” to force through a no-deal withdrawal.

The Queen acts on the advice of her prime minister and is not expected to take an active role herself. Her speech at the opening of parliament is written by the government, outlining its plans for legislation. Her office declined to comment.

"There will be ample time in parliament for MPs (members of parliament) to debate the EU, to debate Brexit and all the other issues, ample time," Johnson told reporters.

Asked if he was trying to block MPs from delaying Britain's EU departure, he replied: "That is completely untrue."

While suspending parliament ahead of a Queen's Speech is the historical norm in Britain, the decision to limit parliamentary scrutiny weeks before the country's most contentious policy decision in decades prompted an immediate outcry.

"Make no mistake, this is a very British coup," John McDonnell, the second most powerful man in the opposition Labour Party, said. More than half a million people signed an online petition to object and the pound fell sharply.

A petition opposing Johnson's decision to suspend parliament gained more than 450,000 signatures in a matter of hours after Johnson's announcement.

The Church of England warned a chaotic Brexit would hurt the poor, the speaker of parliament said the move marked a "constitutional outrage" and a group of cross-party lawmakers sought a legal injunction.

But Johnson's gamble was welcomed by Brexiteers, including Trump, an early backer of Britain's departure from the EU, who said "Boris is exactly what the UK has been looking for, & will prove to be 'a great one!' Love UK."

A spokeswoman for the European Commission, when asked about the British suspension of parliament, said it was a matter for the UK to answer.

Sterling fell sharply, losing around a cent against the U.S. dollar and the euro, as investors took the news as a sign that a no-deal Brexit, and the prospect of a hit to Britain's economy, was more likely.

Reuters