Former Scottish first minister Alex Salmond has accused his successor Nicola Sturgeon of having failed to pursue the case for independence urgently enough.

Mr Salmond, as leader of the new pro-independence Alba Party, is bidding to make a dramatic return to Holyrood almost seven years after stepping down as SNP leader and first minister.

In a thinly veiled attack on Ms Sturgeon, he appeared to side with her critics who claim she has been too cautious in her pursuit of independence.

Speaking on BBC Radio Scotland’s Good Morning Scotland programme on Wednesday, Mr Salmond said: “I think in terms of urgency, in terms of getting on with that job, I am not certain why the case has not been pursued as urgently as it should have been over the last five years, but it should be pursued now.”

He said there is a “growing realisation in Scotland that that should be done”, adding: “People will get very frustrated if we return pro-independence majorities and nothing happens.”

The Alba Party is fielding candidates in all eight regions on Holyrood’s list ballot, and Mr Salmond believes his party can help see a “supermajority” of MSPs in favour of independence elected on May 6.

He said: “Now I think a supermajority… gives a much better chance of it happening in the next Parliament than it happening in the last Parliament.”

Ms Sturgeon has already made clear that if she is re-elected to power next month, her immediate focus will be on continuing to tackle the coronavirus crisis.

But Mr Salmond said: “I think the first job of that new Parliament, with its supermajority, should be to pass a resolution in week one, instructing the Scottish government to open negotiations with the UK Government on Scottish independence, that is the sort of urgency we want to inject into the independence debate.

“If it is a debate that is presented as a Tory Prime Minister against a Scottish Parliament, representing the Scottish people, the new declaration of independence, then Scotland will have a fundamental advantage in these negotiations.

“That’s the importance of getting a supermajority and the opportunity presented by this election.”

He also claimed there are a “range of options” open if Prime Minister Boris Johnson continues to block a second vote on independence.

Mr Salmond said in those circumstances, “the idea of a plebiscite is open” – indicating there could be a vote organised in Scotland.

He said other options include the prospect of either domestic or international legal action against the UK Government, and calling for “international pressure, diplomatic pressure” to be put on Mr Johnson.

Mr Salmond also said: “I do believe that popular and peaceful demonstrations have a role to play in politics.

“But we must cast this debate as a Tory Prime Minister against a Scottish Parliament and a Scottish nation, the whole community of the realm from Scotland.”