Boris Johnson has rejected claims his decision to hold a Queen’s Speech on October 14 is designed to block MPs from considering ways to thwart his Brexit plans after he was accused of mounting a “coup” against Parliament.

The Prime Minister said it was “completely untrue” that Brexit was the motivation for the move, insisting it was time for a new session of Parliament to set out his “exciting agenda”.

But a furious Commons Speaker John Bercow joined a chorus of outrage over the plan, saying he had not been consulted about the move, which he labelled a “constitutional outrage”.

Under the PM’s plan Parliament will be temporarily shut down from around September 11 until the state opening on October 14.

The move led to accusations Mr Johnson was acting like a “tin pot dictator” and dragging the monarch into a bitter constitutional row.

Mr Bercow said: “However it is dressed up, it is blindingly obvious that the purpose of prorogation now would be to stop Parliament debating Brexit and performing its duty in shaping a course for the country.”

The Speaker added that “at this early stage in his premiership, the Prime Minister should be seeking to establish rather than undermine his democratic credentials and indeed his commitment to Parliamentary democracy”.

But Downing Street sources insisted only around four Commons sitting days would be lost due to the suspension of Parliament before the speech, a move known as prorogation.

The Prime Minister said there would be “ample time” for MPs to debate Brexit either side of a crunch EU summit on October 17.

Asked whether the move was because he was planning an early general election before the end of the year, Mr Johnson said: “No, what you should take from this is we are doing exactly what I said on the steps of Downing Street which is that we must get on now with our legislative domestic agenda.”

But shadow chancellor John McDonnell said: “Make no mistake, this is a very British coup.

“Whatever one’s views on Brexit, once you allow a Prime Minister to prevent the full and free operation of our democratic institutions you are on a very precarious path.”

Former chancellor Philip Hammond, who is opposed to a no-deal Brexit, said: “It would be a constitutional outrage if Parliament were prevented from holding the Government to account at a time of national crisis.”

The Prime Minister said he hopes to agree changes to the Brexit deal at the October European Council summit and said there would be time to pass the required legislation before the UK’s October 31 exit date.

But he restated his commitment to leaving the EU “with or without a deal”.

The Commons was expected to sit in the first two weeks of September and then break for the conference recess – although opposition MPs had been considering voting against leaving Westminster for the autumn party gatherings to allow more time to consider Brexit.

Opposition parties had agreed to work together on passing legislation to block a no-deal Brexit when the Commons resumes sitting on September 3.

But Mr Johnson’s move will make sure that the Commons is not sitting during the party conferences – the Tory conference is due to finish on October 2 – and MPs will not return until the day of the Queen’s Speech.

After Jeremy Corbyn led talks which produced a cross-party agreement to work on preventing a no-deal Brexit, Downing Street insiders accused those involved of trying to “sabotage” talks with Brussels.

And in a letter to MPs, Mr Johhnson said EU leaders were watching the actions of MPs: “These weeks leading up to the European Council on 17/18 October are vitally important for the sake of my negotiations with the EU.

“Member states are watching what Parliament does with great interest and it is only by showing unity and resolve that we stand a chance of securing a new deal that can be passed by Parliament.”

Mr Johnson’s approach met with widespread condemnation from MPs opposed to a no-deal Brexit.

Tory MP Simon Hoare said: “This is not ‘taking back control’ it’s certainly not respecting/restoring Parliamentary Sovereignty.

“Rather it’s an executive seeking to abuse one of its (perfectly proper) powers.”

Liberal Democrat leader Jo Swinson, who was one of the MPs at a meeting with Mr Corbyn on Tuesday to agree tactics to prevent a no-deal Brexit, said the Prime Minister was embarking on a “dangerous and unacceptable course of action”.

The announcement of the Queen’s Speech came after Chancellor Sajid Javid fuelled speculation about an early election by bringing forward the date of the spending round which is expected to include crowd-pleasing funding boosts for schools and hospitals.

The move could be a sign the Tories are preparing for an election if MPs across the Commons opposed to Mr Johnson’s Brexit plans bring down the Government through a vote of no confidence.