THE UK and Europe are headed for a “huge geo-strategic mistake” by allowing a no-deal Brexit to happen by accident, the Foreign Secretary has claimed.

Ramping up the government’s rhetoric in the face of EU resistance to the Chequers plan for a soft Brexit, Jeremy Hunt said his warning was not “project fear” but “project reality”.

Mr Hunt made the claim in Vienna alongside his Austrian counterpart Karin Kneissl.

However Ms Kneissl, whose country holds the rotating EU presidency, downplayed the prospect of the UK and Europe failing to reach a deal on trade and customs by March 2019.

“From the [European] commission’s side there is a clear-cut schedule, so an accident is not really something people are working for,” she said, calling her talks with Mr Hunt “excellent”.

But Mr Hunt was adamant the UK would not blink in negotiations, despite Europe saying parts of the Chequers plan are unworkable and a potential smugglers’ charters.

The UK’s proposal would maintain a “common rule book” on goods and agri-foods, but avoid current restrictions on services and migration, something the EU regards as cherry-picking.

Mr Hunt said: “We have to make a decision on Britain’s future relationship with the EU by the end of this year and we have to be very honest with ourselves about the choices that we face. At the moment we are heading for no deal by accident.”

Despite Theresa May insisting a no-deal Brexit would be better than a bad deal, Mr Hunt said a no-deal legal and regulatory cliff edge would be a “huge geo-strategic mistake” with “a profound impact on the relations between Britain and EU countries for a generation”.

His comments coincided with Sky News revealing dozens of internal council plans to cope with a no-deal, including preparing for the possibility of social unrest.

Dover District Council and Kent County Council are preparing for a 13-mile lorry park on the M20 southbound for at least four years to cope with tailbacks at ports.

Pembrokeshire is concerned about food supplies, East Sussex fears care staff would quit the country, while Bristol says its top-line threat is “social unrest or disillusionment”.

One of the most common complaints among councils was a lack of direction from Whitehall.

Kevin Bentley, chair of the Local Government Association Brexit Taskforce, said leaving the EU would have a "significant impact" on councils.

The Government said it was “confident we will secure a positive agreement with the EU”, but was working closely with councils to plan for all scenarios.

Theresa May, who interrupts her holiday tomorrow to visit France’s President Macron to push the Chequers plan, will have to make "significant" concessions to get a deal, a respected thinktank said.

The National Institute for Economic and Social Research said the PM would have to pay more cash to the EU and accept higher migration, and warned an “epidemic of uncertainty” was already affecting the nation and its economy.

It said a no deal Brexit would end up costing the UK economy £800 per person per year in lost output, while even the softer Chequers plan would cost £500 per head.

SNP MP Peter Grant MP said the warning had “fallen on deaf ears” in Theresa May’s cabinet.

He said: “The comments from the Foreign Secretary that the likelihood of a no-deal is increasing by the day, and that the UK government will not blink in its negotiations with the EU, are unbefitting of the office he holds. It’s time that reckless rhetoric was brought to an end.”