Boris Johnson’s government believes it may be able to strike a series of quick side deals to keep vital trade flowing in the event of a no-deal Brexit once EU countries feel the disruption, HuffPost UK has learnt.

The government believes individual EU members will demand that Brussels strikes agreements with the UK to protect businesses in their own countries which will be worst-hit by no deal.

The EU has so far remained united in refusing to discuss the idea of side deals in key areas of trade, but ministers believe the pain of no deal on both sides of the Channel could force Brussels to the table.

The prime minister has attempted to play down the chances of no deal in recent days as the pound slumped with markets reacting to his “do or die” pledge to leave on Halloween.

But negotiations are locked in stalemate, with Johnson refusing to sit down with EU leaders unless they agree to reopen the withdrawal agreement, an idea which Brussels has rejected.

Since becoming PM last Wednesday, Johnson has tasked Michael Gove with “turbo-charging” the government’s domestic plans for no deal, taking responsibility away from Brexit Secretary Stephen Barclay.

But Barclay, who will play a key role in any new withdrawal agreement talks, is also working on plans for side deals.

He is establishing the key areas where deals would need to be done to minimise disruption.

And he is working out how the UK may be able to leverage individual member states to put pressure on Brussels, for example by offering to continue to recognise EU geographical indications that protect producers of French champagne or Italian Parma ham in return for good trading terms.

Ministers also feel that countries which rely on UK waters for fishing could be keen to mitigate the worst impacts of no deal.

The likes of Ireland, France, the Netherlands and Belgium, which trade closely with the UK, are being seen as potentially the most amenable to the idea, despite repeated EU warnings that there will be no side deals.

Meanwhile, Johnson’s senior Europe adviser, David Frost, is visiting Brussels for talks with senior officials over the coming days.

Downing Street said Johnson’s “sherpa” will deliver the PM’s message that the UK will leave the EU on October 31 “whatever the circumstances”.

He will meet officials including the head of European Commission president Jean-Claude Juncker’s cabinet and Stephanie Riso, a senior figure in Michel Barnier’s Brexit negotiation team.

But Annika Breidthardt, a spokeswoman for Juncker, played down the prospect of Frost’s meeting being the start of fresh negotiations.

“It’s a new sherpa, our officials always meet with the sherpa so it’s a meeting on that basis,” she said.

Frost left his role as chief executive of the London Chamber of Commerce and Industry to take up his job in Johnson’s administration.

He replaced Olly Robbins, whose efforts to negotiate a deal with Brussels had made him a target for Brexiteer criticism.

In an email to counterparts in the 27 other EU states, Frost warned them not to “underestimate” Johnson.

The missive, seen by the BBC, said “many people are inclined to underestimate Boris Johnson and I would urge you not to do so” adding “that you should be in no doubt about this government’s commitment to the October 31 date”.

It came as Sinn Fein warned Johnson that a failure to hold a vote on Irish reunification in the event of a no-deal Brexit would be “unthinkable”.

Party president Mary Lou McDonald and senior colleagues pressed the case for a border poll during a bilateral meeting with the PM at Stormont, in Belfast.

“The way out of this for Ireland, if he is intent on crashing, if that’s the outcome, the way out for us democratically is to have a border poll and to allow Ireland and Irish people to decide our future,” she said.