SCOTTISH Labour has been warned of “sliding into irrelevance” and “running scared of democracy” after Richard Leonard said his party would fight a General Election on a commitment to oppose a second independence referendum.

He came under attack from Nicola Sturgeon and her deputy Keith Brown who said Leonard was positioning his party in such a way that would keep it “alienated” from former supporters who backed Yes.

“Scottish Labour’s determination to remain alienated from swathes of its previous support as it attempts to out Tory the Tories on #Indy shows no sign of abating. Which can only be good news for @theSNP,” the First Minister tweeted.

Leonard made the policy announcement three days after UK Labour leader Jeremy Corbyn said he would not rule out giving the Scottish Government the power to hold an independence referendum if he became Prime Minister.

The Scottish Labour leader told the BBC Sunday Politics show: “We want to be absolutely clear to the people of Scotland that there is no case for a second independence referendum, we just had a referendum in 2014, we think that settled the will of the people of Scotland and I don’t think there is any support for a second independence referendum – which is why we are going to categorically in our manifesto in the lead up to the general election, which may come as soon as later this year, state our opposition to the holding of a second independence referendum.”

Brown said the SNP had a clear mandate for a second independence referendum after his party’s 2016 Holyrood election manifesto set out the case for a new vote if there was a significant change in circumstances such as Scotland being taken out of the EU against its will. That position was subsequently backed by a majority of MSPs in a Holyrood vote.

“We would like to thank Labour for ruling themselves out of winning the next election in Scotland,” Brown said.

“There is already a cast-iron democratic mandate to give the people of Scotland that choice based on the 2016 Holyrood election and the subsequent vote in the Scottish Parliament.

“By blocking any attempt to allow the people of Scotland to have their say on their constitutional future, Richard Leonard is not only running scared of democracy – he is alienating many of Labour’s traditional supporters in the process.

“Labour are now on their fifth leader in Scotland since the independence referendum – and in the face of soaring SNP membership numbers and historically high levels of support for independence, Mr Leonard has shown that he has not learned why they have suffered repeated election disasters in recent years.”

He added: “The only people who should be allowed to determine Scotland’s future are the people of Scotland themselves – for as long as Labour fail to understand that, they will continue their slide into irrelevance.”

Patrick Harvie MSP, the Scottish Greens’ co-convener, said: “Once again Labour are giving us a whole series of hypotheticals, but for argument sake, is Richard Leonard really saying that a Westminster Labour government would ignore a majority vote at Holyrood, while at the same time continuing to drag us out of Europe against the clear will of voters in Scotland?

“That’s no way for Corbyn’s Labour to respect Scotland, or protect the national interest.”

Leonard’s intervention comes just weeks after an opinion poll by Deltapoll found 47% of Scots would back a Yes vote if a referendum was held after Brexit, with 43% voting No. Removing “don’t knows”, the result was 52% Yes, and 48% No.

Leonard will tell his party conference in Liverpool today “that Scotland does not need another vote on independence, but the election of a Labour government”.

In the interview with the BBC yesterday, Leonard would not confirm whether or not he had discussed his manifesto announcement with Corbyn.

Asked whether he has spoken to Corbyn and got his agreement that a future Labour government will not authorise a second independence referendum, he replied: “I speak to Jeremy Corbyn on a regular basis.

“We will be drawing up our manifesto because there is every prospect of there being an early General Election and what I’m saying to you is that as somebody who will be a party to the drafting of that manifesto, I will stand resolute on the question that there should not be a second independence referendum, and I am expecting to get the support of the whole of the Labour party on that question.”

The independence referendum in September 2014 was held after the Scottish and UK Governments signed the Edinburgh Agreement, allowing the vote to take place and committing both sides, north and south of the Border to respect the final result.