Scotland’s Constitutional Secretary, Michael Russell, said he hoped that a government motion making clear Holyrood’s opposition to a no-deal Brexit “in all circumstances” would be passed unanimously.

The motion has already won the support of Labour, Liberal Democrat and Green parties, piling pressure on the Scottish Conservatives to back it, given their leader Ruth Davidson’s public remarks that she cannot back a no-deal Brexit.

While it is yet to be approved at Holyrood’s business bureau, the motion is expected to say: “That the Scottish Parliament agrees that the UK should in no circumstances leave the EU on a no-deal basis.”

Nicola Sturgeon appeared at the Beyond Borders Book Festival on Sunday. The Scottish Government is expected to bring forward motion against no-deal this week

Mr Russell said: “When the new session starts we will be less than two months away from a catastrophic no-deal which the UK government appears now to be actively pursuing.

“It is essential that the Scottish Parliament has the opportunity to have its say while there is still time to stop this disaster from happening. It is more important than ever for politicians and parties to work together in Scotland and across the UK to do as much as we can to make the new Prime Minister change course.”

He added: “For the Scottish Tories this could be a defining moment. Their leader in the Scottish Parliament says she is opposed to a no-deal Brexit. This is an opportunity to make that opposition crystal clear and unambiguous. Crashing out of the EU without a deal is in no one’s interest.”

Scottish Conservative MSP Donald Cameron said: “The Scottish Conservatives agree that the best way to leave the EU is with a deal.

“That’s why all 13 of our MPs backed a deal, and are continuing to back the Prime Minister’s efforts to get another deal secured. If the SNP and Labour believe that a no-deal would be as bad as they say it is, they need to explain why they have continually blocked attempts to get a deal over the line.”

Scottish Liberal Democrat leader Willie Rennie and Scottish Greens co-leader Patrick Harvie both confirmed their parties would back the motion.

Mr Rennie said: “The overwhelming majority of the public across the whole of the UK are opposed to a no-deal Brexit.

“This parliamentary debate is an opportunity for all parties to come together and urge the Prime Minister to change course. I hope that will include Ruth Davidson, who once warned of the damage Brexit would do to our economy and way of life.”

MSPs will return to Holyrood on 3 September, just three days before a Brexit petition brought by a cross-party group of MPs will be heard at the Court of Session in Edinburgh. The petitioners are asking for a “declarator” that the Prime Minister cannot legally advise the Queen to suspend parliament in the run up to the Brexit deadline of 31 October.

The group – which includes Liberal Democrat leader Jo Swinson, Scottish Labour MP Ian Murray and SNP MP Joanna Cherry – want the court to rule such a move as unlawful and beyond the powers of the government.

Boris Johnson has repeatedly refused to rule out the prorogation of Parliament, and a leaked government email in a Sunday newspaper revealed that he had asked for advice from the Attorney General, Geoffrey Cox, as to whether the House of Commons can be shut down for five weeks.

Yesterday SNP Westminster leader Ian Blackford said a Parliamentary shutdown would be “outrageous”. He added: “Boris Johnson cannot be allowed to trample over democracy. He must ditch his plans to drag Scotland and the UK off the Brexit cliff-edge.”

Scottish Tories under pressure to back Holyrood motion against no-deal Brexit