ALEX Salmond has said it is in the "Scottish national interests" for people to vote for Alba on the regional list at next month's election.

The former first minister, who is heading the new independence party, made the claim as he argued next month's election is "about putting nation before party" to achieve an independence "supermajority" in Holyrood.

His party is standing four candidates in all eight electoral regions of Scotland, but is not standing in any of the country's 73 constituencies, where it is advising people to vote for the SNP.

Alba believes a Yes supermajority will strengthen the parliament's negotiating power with Boris Johnson's government at Westminster in the independence fight which has repeatedly refused to agree a new referendum with Nicola Sturgeon's government.

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"We need to come together, to work to create a Parliament which encompasses all shades of opinion prepared to back Scottish independence," Salmond told supporters and journalists at his party election campaign launch this afternoon.

"The Tory Prime Minister must not be allowed to cast this great debate as party against party, Prime Minister against First Minister.

"If he does that, Scotland will lose. This needs to become what we all know it to be - a Tory Prime Minister standing against the will of Scotland’s Parliament representing Scotland‘s people. Boris Johnson has already declared he will ignore an SNP victory as a basis for a referendum.

"But even if he can ignore a party, he cannot ignore a Parliament and a nation."

Salmond said that an independence supermajority would issue a "a clear and unmistakable instruction to the Scottish Government to open negotiations with Whitehall on independence" and that this should take place in the first week of the new Parliament and could include a new attempt to get an agreed referendum through a Section 30 order.

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The former SNP leader added that a cross-party Independence Convention could be established to support the Scottish Government’s negotiations.

"A Section 30 referendum could be part of that, as could a plebiscite, or another democratic test as could domestic legal action or international and diplomatic initiatives, as could peaceful and popular demonstration," he said.

"The tactics will inevitably evolve with the negotiations but the strategy is to make the achievement of Independence a real and overriding priority."

He added: "The key to all of that is to elect the maximum number of independence supporting MSPs. I’ll be voting SNP with my first constituency vote for that reason.  I know tens of thousands of SNP supporters are going to vote for Alba on the list for exactly the same reason. Because it is in the Scottish national interest to do so.

"In that unity and common purpose lies our strength and our greatest opportunity to deliver independence. That approach can deliver a shared parliamentary purpose in Holyrood which changes the context of the debate and which tilts the balance of power in Scotland’s favour.

"It is the only way to guarantee that Scotland cannot again be sidelined and to ensure that democratic expression will prevail .. .It is time for nation before party. "

During Alba's virtual campaign launch Salmond, speaking from Ellon, said a series of policy papers would be presented to voters in the coming days and next week, including ones on Europe, economic recovery, women and inequalities and on education.

A Panelbase poll at the weekend put Alba on course for six per cent of the vote share, which would give them six MSPs, with the SNP on course for 65 seats and the Greens eight.

This would mean 79 pro-independence MSPs out of 129.

Discussing the survey today Salmond said he believed the Yes majority could be even bigger.

He said: "The Sunday Times poll at the weekend that suggested almost 80 independence supporting MSPs if you count the SNP, the Green party and Alba together.

"I think we can go higher than that but that of course depends on the verdict of the people. If you take where I am just now in the north east of Scotland there were 137,000 SNP votes on the list ballot in the last Scottish parliament elections. They elected precisely zero MSPs from that list ballot."

During the campaign launch, Salmond read out Alba's new Declaration for Scotland.

It said: "We hereby proclaim the sovereign right of the Scottish people to determine the form of Government best suited to their needs, and declare and pledge that in all our actions their interests shall be paramount.

"We further declare and pledge that our deliberations shall be directed to the following ends:

"To assert the sovereign right of the Scottish people acting through their Parliament to secure independence.

"To mobilise Scottish and international opinion to ensure that this right is respected and acted upon.

“For in truth it is not glory, or riches, or honours for which we are fighting but for liberty - for that alone, which no honest person gives up but with life itself.”

But First Minister Nicola Sturgeon has been critical of Salmond's Alba party, which has taken a number of its senior figures, including MPs Kenny MacAskill and Neale Hanvey.

In an interview last week she said she is concentrating on winning a “simple majority” for the SNP ahead of the Scottish Parliament elections on May 6 and accused Salmond of taking a gamble on the voting system.

She was asked on BBC Good Morning Scotland last Thursday whether Scotland’s additional member system means a list vote for the SNP could potentially be a waste. However, she dismissed this and the plan put forward by Salmond.

“You only have to cast your mind back to the days when Alex Salmond was leader of the SNP and he didn’t say what he is saying now,” Sturgeon said.

“What he said then, and he was right then, is that the only way to make sure you get the government you want is to vote for the party that will be that government.

“Anything else is trying to gamble with the system, game the system, take a chance on the outcome of the election.

“And if you want to see an SNP government elected that then has the ability to deliver an independence referendum, then you don’t get that by voting for somebody else – you only get that by voting SNP.”