Anas Sarwar will resign as Scottish Labour leader to take a seat in the House of Lords and a ministerial role in Andy Burnham’s government.

Mr Sarwar, who called for Sir Keir Starmer to resign during the Scottish election campaign, will join the newly-formed Department for Business, Innovation, Science and Trade.

He was in the audience when Mr Burnham delivered his first speech as Labour leader on Friday and has hailed the “bold Labour vision” set out by the new Prime Minister.

He is among Mr Burnham’s junior ministerial appointments and his departure from Holyrood will prompt a leadership campaign, with Michael Marra expected to be the frontrunner to replace him. There will not be a by-election as Mr Sarwar was elected via the regional list.

Mr Sarwar has been barely visible since May when he led Scottish Labour to its worst election result, leaving his deputy Jackie Baillie to issues public statements.

He is expected to become a business minister in the new department which is formed following the controversial abolition of the Department for Science, Innovation and Technology. Jonathan Reynolds, who was sacked by Sir Keir as Business Secretary, has been reinstated in place of Peter Kyle.

SNP depute leader, Keith Brown, accused Mr Burnham of damaging Labour’s democratic credentials by installing Mr Sarwar into the Lords and role in the UK government. It followed Mr Burnham flatly rejecting SNP leader and First Minister John Swinney another referendum on independence.

“This is a terrible look for Andy Burnham who waxed lyrical about a new politics and devolving power – he’s just pulled the most undemocratic trick in the Westminster book,” said Mr Brown. 

“Anas Sarwar led Scottish Labour to their worst ever election defeat, but as is always the case with the Labour Party, there’s always a cushty number in the House of Lords. 

“What a signal to send after their democractic defeat – this is the Labour Party literally lording it over the people of Scotland.

“This morning Andy Burnham denied Scottish democracy in a phone call with Scotland’s First Minister, tonight he appoints a failed Scottish Labour leader to the Lords. This new Labour Government has deeply damaged its democratic credibility tonight. 

“Andy Burnham raised the question of where power lies on these islands – it’s clear the Labour Party are still stubbornly determined to keep it firmly in the grip of a detached and undemocratic Westminster establishment.”

Reform UK Scotland deputy leader and MSP for Glasgow Thomas Kerr said: “Only weeks ago, Anas Sarwar stood before the people of Glasgow asking for their trust and insisting that his future was here in Scotland. Today, those same voters will rightly feel betrayed.

“Throughout the election campaign, he dismissed suggestions that he had ambitions elsewhere and claimed his focus was on serving Scotland. Now, at the first opportunity, he has walked away from the very people who placed their faith in him.

“This is yet another example of Labour abandoning Glasgow when it becomes politically convenient. The people of this city deserve representatives who will stand and fight for them, not politicians who treat public office as a stepping stone to their next job.”

Scottish Conservative deputy leader, Rachael Hamilton said: “Anas Sarwar repeatedly told Scots his only focus was serving Scotland and becoming First Minister.

“He’s walking away from that pledge for a peerage and a ministerial job in Westminster.

“Given he was one of the loudest voices calling for Keir Starmer to go, people will inevitably ask whether he always had one eye on a role at Westminster. Scottish voters will rightly feel they’ve been let down by yet another Labour broken promise.”

Scottish Green Party co-leader Gillian Mackay said: “Anas Sarwar is a chancer. He has gone from promising to scrap the House of Lords to taking a seat in it. 

“He has spent years attacking the very institution he is now preparing to join. The hypocrisy is breathtaking.

“If he cannot stand by his most basic political principles when power is on offer, why should anyone believe a word he says about anything else?

“By grabbing a place on the unelected red benches, he’s ensured that he gets all of the power and privilege without having to worry about what voters might think.

“This is bigger than Anas Sarwar. It is about the contempt that the system shows for democracy. 

It is clearly not right or fair for politicians who have been rejected by the country to end up as law makers for the rest of their lives safe in the knowledge that there is nothing anyone can do to stop them.

“One of the many joys of independence will come when we are finally able to abolish the broken and arcane relic that is the House of Lords and build a modern democracy.”