THE SNP's Angus MacNeil has renewed his call for next year's Holyrood election to be an effective referendum on independence.

MacNeil has previously argued for his party to use such an alternative route to independence if Boris Johnson continues to refuse to give powers to the Scottish Parliament to hold a legally-watertight new vote.

The MP for Na h-Eileanan an Iar has now reiterated his views in response to an intervention from leading pollster Professor Sir John Curtice.

In a newspaper interview Professor Curtice suggested that the 2024 General Election could be used as an effective independence referendum if the UK Government continues to ignore calls for a second vote.

Sir John, who is professor of politics at Strathclyde University, argued the SNP could adopt a position at that election that a majority of Scottish seats at Westminster could be justification for independence – a move back to the party’s pre-devolution perspective.

Speaking to The Courier yesterday, he said: “If the SNP get an overall majority at Holyrood on their own next year, which I think is the condition they will have to satisfy, and by one means or another the UK Government says no, then you have to ask what position they will adopt in response.

“One possibility would be to say that if the UK Government is not willing to accept a referendum, then they would regard forthcoming elections as indeed a vote on independence.”

Responding to Curtice's comments, MacNeil tweeted: "Or the 2021 Scot election if Scots prefer not to have 3 needless years of Boris."

First Minister Nicola Sturgeon earlier this month announced the Scottish Government would publish a draft bill setting out the terms, question and timing of a second independence referendum.

She told Holyrood the document would be published within the current Scottish parliamentary term which ends in March.

Announcing her programme for government to MSPs, the First Minister said at next year’s election she will “make the case for Scotland to become an independent country, and seek a clear endorsement of Scotland’s right to choose our own future”.

The SNP is on course to secure a majority at next year’s Holyrood election and to take a record fourth term in government.

A series of recent polls have also found there is majority support for independence, with one survey suggesting 55% of Scots backed Yes, while 45% backed the Union – reversing the result of the referendum held on 18 September 2014.

On Wednesday, the Prime Minister was asked by MacNeil, who is chair of the international trade committee in the Commons, whether he will ever agree to a section 30 order.

Johnson said: “The Scottish Nationalist Party fought the referendum in 2014 very clearly on the understanding that it was a once in a generation event.

“It was something that I believe both Nicola Sturgeon and Alex Salmond said at the time in persuading people to cast their votes."

MacNeil and Inverclyde councillor Chris McEleny last year tried to get the SNP to back a Plan B route. But their attempts were defeated following a stormy debate at the party’s conference in Aberdeen.

Last month Sir John cautioned the SNP against putting a Plan B route to independence in its Holyrood manifesto warning it could weaken its negotiating position with Johnson to get a section 30 order.

The leading academic said the party would need to present a clear position to voters before the 2021 election about what it sought from the Prime Minister.

An inclusion of an alternative process to independence could risk such clarity and “let Johnson off the hook”, he told The National.

“If you want to maximise the pressure on the UK Government you don’t want to tell them what your Plan B is. If you want the result of the election next year to maximise the pressure on the UK Government, then you want to be able to say. ‘We went to the people, the people have said yes, so can we please have our referendum in exactly the same way we did in 2014.'"