NICOLA Sturgeon has warned that a no deal Brexit is "almost inevitable" after No 10 ruled out extending any transition period if Boris Johnson is returned as prime minister in a general election.

Under the prime minister's proposed deal, the UK will continue to follow EU rules after it has left the bloc until the end of 2020 to allow the two sides to negotiate a new trade deal.

The prime minister's official spokesman said the government would not be seeking any extension to that believing that is sufficent time to get a trade deal.

That would mean the EU and the UK will have less than a year to hammer out and finalise a free trade agreement.

Number 10 has insisted that the December 31, 2020 deadline will be stuck to after Work and Pensions Secretary Therese Coffey appeared to suggest it would be tough to meet.

"The government will not be extending the transition period. The prime minister believes that we will have a good trade deal agreed with the EU by December 2020," the spokesman said.

"The Brexit process has been going on for long enough."

Critics believe there is no chance of the two sides getting everything done in such a short space of time and the divorce deal does include the option of a delay of up to two years.

The First Minister, who has been dancing at Lochside Community Centre in Dumfries while on the General Election campaign trail warned: "This makes a no deal Brexit a significant risk - in fact, given the likely impossibility of agreeing a trade deal in less than a year, it would make it almost inevitable. In a nutshell, this is a reason to get Tory MPs out."

Earlier Therese Coffey, a pensions minister, opened the door to extending the transition period past 2020 on Sky News after presenter Kay Burley pointed out no country has managed to do a deal in ten months.

"We're starting off with the same rules, the same tariffs, it should be straight forward to try and agree that deal.

"Nothing is ever straight forward, I think we've learned that from the last three years but it can be more straight forward if Boris Johnson is in charge with a majority Conservative government so we can actually get on with Brexit".

International trade agreements often take years to complete - a new deal between the EU and Japan took the best part of six years to negotiate.