Pound slumps as UK confirms Queen's Speech for Oct 14

The timing of the speech, which sets out the government's future plans, would thwart efforts by pro-European MPs to stop a no-deal Brexit, although Johnson denied this. The Queen approved his request mid-afternoon after a meeting with senior Conservatives at Balmoral castle.

"If you look at what we’re doing we are bringing forward a new legislative programme on crime, on hospitals, making sure that we have the education funding that we need and there will be ample time on both sides of that crucial 17 October (EU) summit, ample time in parliament for MPs to debate the EU to debate Brexit and all the other issues," Johnson said on Wednesday.

The pound was down 0.9% against the US dollar at 1.2180 and slumped 1.1% against the euro at 1.0966.

House of Commons speaker John Bercow called the move a "constitutional outrage”.

"However it is dressed up, it is blindingly obvious that the purpose of prorogation (suspending parliament) now would be to stop parliament debating Brexit and performing its duty in shaping a course for the country."

“Shutting down parliament would be an offence against the democratic process and the rights of parliamentarians as the people’s elected representatives," he said in a statement.

“Surely 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."

Johnson sought legal advice about proroguing parliament for five weeks from early September, leaked emails published on the weekend revealed. Critics of the move say parliament is being denied a role in the process to appease Conservative Brexit ultras who want to leave the European Union irrespective of the cost.

XTB chief market analyst David Cheetham said the move appeared to be "a pre-emptive strike from Boris against those seeking to block a no-deal Brexit and once more it seems that the opposition are in danger of fluffing a big opportunity to have an impact".

"If the government is successful in this then a no-deal Brexit wouldn’t be taken off the table until the 11th hour at the earliest and this keeps a significant downside risk to the pound in play."

Oanda analyst Craig Erlam said: "This isn't the first we've heard of these dirty tactics but it was maybe hoped that such un-democratic measures would not be needed or used. Some may have thought them inevitable but perhaps not at this point in the process."

"Either way, it certainly caught markets off-guard and came at a time when the pound had been recouping some of its losses."

Berenberg chief economist Holger Schmieding said: "In a way, a need for a Prime Minister to suspend his own parliament because he seems to lack a majority for his key policy - the approach to Brexit - is not exactly a sign of strength, to put it mildly."