More divisions have emerged in the SNP as Deputy First Minister John Swinney faces accusations of telling party members how to vote for the next leader.

Mr Swinney, who chose not to run despite being pencilled in as the early favourite, has thrown his support behind Health Secretary Humza Yousaf. His endorsement follows support for Mr Yousaf from Westminster leader Stephen Flynn and his deputy Mairi Black.

The Deputy First Minister said Mr Yousaf would strengthen the party “as a force for progressive change”.

In what some will see as a criticism of Kate Forbes’ lack of commitment to the SNP’s Green party partners, Mr Swinney said: “Humza will govern effectively by using the partnership that we enjoy with the Scottish Green Party – guaranteeing us a pro-independence majority in the Scottish Parliament.”

He added: “Humza will widen our support in attracting new supporters to Scottish Independence. Humza is an experienced Minister who’s done all the tough stuff that you have to do day in day out within Government.”

But MSP Michelle Thomson, who is backing Ms Forbes, criticised Mr Swinney’s statement. She said: “When the current Deputy First Minister decides to personally intervene in the leadership contest at such a late stage, you get the sense that senior figures in the party have seen the polls and are absolutely panicking. 

“Given how close we are to the vote opening, many party members will look upon this 11^th hour intervention rather cynically. They don’t need to be told by party HQ what to think or how to vote. 

“It increasingly looks like the top brass would much prefer an establishment transfer of power – to carry on with the status quo – rather than allowing our membership the freedom to make a healthy democratic choice.

“I certainly trust our members to be independent-minded and firmly believe they can make their own minds up on who best serves the party, the country and – crucially – can deliver independence for Scotland. There is no doubt in my mind that that leader is Kate Forbes.”

Mr Yousaf said: “I am honoured to have the backing of a true giant of the SNP and independence movement, John Swinney, to become SNP leader.”

Earlier, he made his first comments on economic affairs with a focus on workers’ rights and doing what he can to ensure the Tories’ ‘Minimum Services Bill – which limits the right of workers to strike – will not be enacted in Scotland.

“As part of building a wellbeing economy we know that progressive workplace policies deliver better results,” he said.

“That’s why I’ll support my Westminster colleagues fighting to cut zero hours contracts, support improved parental leave and flexible working, and am open to ideas like the four day working week which evidence increasingly shows makes people more productive and is better for business.

“As First Minister I will also invest in the skills, training and opportunities that will make it easy for workers in industries like oil and gas to move to well paid good jobs in our new renewable industries.

“It is only with independence that we can properly put in place the entitlements that workers deserve, improve the minimum wage, end age discrimination, and scrap anti-trade union laws.

“With independence we can introduce a proper social partnership between government, unions and employers working together to drive the economy forward, an approach that is so successful in so many of our European neighbours.”

Ms Forbes said the party has failed to properly prepare for independence, and said it was necessary to build new organisations to cover reserved matters including energy, finance and foreign affairs – so the public could have greater confidence in the case for change.

“The harsh truth is the groundwork isn’t quite there,” she said.

“For example, we need to plan for the building of a Scottish civil service to cover all the functions of an independent country. A lot of our public bodies are currently constrained by devolution, and we also need new institutions for energy, financial regulation and foreign affairs.

“Let’s engage professionally with the international community so we can ensure we are given international legitimacy – that means serious dialogue with bodies like the UN and the EU.”

Ash Regan has declared that if Scotland votes in an election for independence “there is no possibility of the UK Government not agreeing, as demonstrated in the 65 examples of countries that have left the UK or British Empire. 

“There is a 100% success rate in those countries getting the UK Government to the negotiating table after an initial refusal. It is not credible to suggest anything else, the UK Government will even concede this fact.”