SENIOR figures across civic Scotland have demanded Brexit is delayed in order to avoid the "chaos" of the UK leaving the European Union without a deal.

Leaders in the business, trades union, charity and higher education sectors are behind calls to pause what promises to be the biggest economic change in the UK in over 70 years.

Their call, which is echoed by the SNP, Scottish Liberal Democrats and the Greens, comes as the Prime Minister plans to unveil her Brexit "plan B" to MPs tomorrow.

Under the terms of the 2007 Lisbon Treaty, the UK is scheduled to leave the EU on March 29, two years after Theresa May invoked the so-called Article 50 which sets a time limit on negotiations.

However, with Parliament rejecting the withdrawal plan presented by Theresa May, the prospect of the UK coming out of the 28-member bloc without a deal grows by the day.

Various reports have warned that no deal would have negative economic consequences for the UK, with shortages of medicines and huge tailbacks at ports being predicted.

Although March 29 is the official leaving date, an extension to the process can be granted by EU member states if the UK makes a request.

A range of high-profile bodies in Scotland has intervened by calling for Brexit to be delayed. Anna Fowlie, chief executive of the Scottish Council for Voluntary Organisations (SCVO), which has around 2,000 members, said:

“After two years, we find ourselves on the brink of exiting the EU without a withdrawal agreement that both the UK Parliament and the EU can sign up to.

“There is therefore no choice but to seek agreement with the EU to extend Article 50 to allow time for a second EU referendum to take place.”

Liz Cameron, director and chief executive of the Scottish Chamber of Commerce, said: “The rationale for a delay to the Article 50 timeline is growing each and every day in our business communities.

“An extension to Article 50 would, first and foremost, avoid a no deal outcome on March 29, but it would also acknowledge that neither business nor government are prepared for such a scenario.”

Colin Borland, director of Devolved Nations at the Federation of Small Businesses (FSB), which has around 19,000 members, said: “This longer window could give Scottish business a much-needed opportunity to prepare while taking the fever out of the public debate.”

And David Watt, executive director of the Institute of Directors in Scotland, said business leaders are “very concerned” about a no-deal Brexit: “With all of this in mind, the inevitable conclusion is to extend Article 50. It may be the only option to ensure a deal and a reasonable transition period.”

Grahame Smith, general secretary of the Scottish Trades Union Congress, which represents around 540,000 trade unionists, also backs an extension, as does GMB Scotland Secretary Gary Smith.

Professor Sir Anton Muscatelli, principal of Glasgow University, is also strongly in favour of hitting the pause button as a way of delivering another referendum.

"With the Prime Minister’s deal dead and Parliament in gridlock, there is only one way out – that is to request an extension to Article 50, and call a People’s Vote,” he said.

He added that an extension would “appear the only opportunity to avoid the chaos of a No Deal outcome”.

In today’s Herald on Sunday, the senior civic figures are joined by First Minister Nicola Sturgeon, Scottish Liberal Democrat leader Willie Rennie and Scottish Green co-convener Patrick Harvie.

It also comes after three former Prime Ministers – John Major, Tony Blair and Gordon Brown – called on Article 50 to be either extended or revoked.

Major, who was a Tory PM between 1990 and 1997, has said revoking Article 50 is the “only sensible course”, as a no-deal Brexit would be “morally reprehensible.”

Blair said he would be discussing the terms of an extension with the EU if he was still in Government, while Brown called for Brexit to be delayed by a year.

May’s minority administration is opposed to an extension, but the Prime Minister has not ruled it out.

However, the move would anger her pro-Brexit backbenchers and likely lead to further Cabinet resignations.

Boris Johnson, the Brexiteer who quit as May’s Foreign Secretary in protest at one version of her deal, warned against an extension:

"It would be so utterly pathetic that I do think it would not only cause widespread international dismay but also reinforce people's view that there is some sort of plot at Westminster to stop this thing (Brexit)."