A new attempt to oust Richard Leonard as Scottish Labour leader is being considered by senior figures within the party as they warn the move is now necessary to save it from “annihilation” in next year’s Holyrood elections.

“If Richard stays as leader, Scottish Labour is finished,” declared one leading insider.

Another, a former minister, warned that Scottish Labour was facing an existential threat. “Keir knows the position. Lots of people are saying we are heading towards annihilation.

“There is a strain of thinking that says: if we let Richard stay and he loses at the Holyrood election, then he will go and we will recover. The trouble is, it will be too late by then; we would have lost half of our MSPs, lost public confidence and we might even have been overtaken by the Greens. The position would be irrecoverable.”

But Mr Leonard made clear to The Herald he was going nowhere and intended to lead Scottish Labour into the May elections “on a transformative socialist platform to revive the economy in post-Covid Scotland”.

In September, an attempt was being prepared at the party’s Scottish National Executive to oust the leader. It followed MSPs Mark Griffin, Daniel Johnson, James Kelly and Jenny Marra telling Mr Leonard they had lost confidence in him and urged him to stand down to avoid an electoral “catastrophe” in May’s poll.

But the vote of confidence was pulled with just minutes to go after trade unions got “cold feet” and withdrew their opposition to the leader continuing in post.

However, Labour insiders close to Sir Keir Starmer say he remains privately convinced Mr Leonard has to go not just for the sake of the Scottish party’s survival as a political force but also for the sake of his own chances of getting into No 10 in 2024.

Yet, the UK party leader is said to be caught in a dilemma; unsure if it is wise to risk a new row over ditching the Central Scotland MSP as Scottish leader in the run-in to May’s poll given the strong resistance to such a move among some left-wing supporters.

Senior figures are calling on Sir Keir to pressure the trade unions to use their influence to get Mr Leonard to resign.

One told The Herald: “The unions are key. Keir needs to pick up the phone and talk to them.”

Another said: “We need to have a last go at a vote of confidence because if we wait until May, it’s all over; regardless of how difficult this is and how much blood there might be on the carpet.

“We might not even get to a formal vote; it might be a case of presenting to Richard the evidence he is going to lose a confidence vote and try to give him a dignified exit.”

Asked if Sir Keir believed Mr Leonard had to go, one senior colleague said: “He’s convinced it’s the right thing to do; I’m not sure he’s convinced it’s deliverable.”

But asked if, nonetheless, a fresh attempt to oust the Scottish leader was now being seriously considered at the highest party levels, he replied: “Yes, absolutely.”

Labour sources suggested Mr Leonard had convinced himself that he could turn things round despite the dwindling poll ratings.

But one peer noted: “Richard has tried but it’s not working. The plea should be to his conscience. He needs to do what is necessary to save the party; that’s the key thing. There is no personal animosity towards him; he should just step aside and let someone else come in who can mobilise Scottish Labour.”

Names mentioned by party figures as a possible successor to steady the ship include MSPs Jackie Baillie, Sarah Boyack and Anas Sarwar.

The latest polling on Holyrood’s constituency vote, conducted last week by Ipsos Mori for STV News, placed Scottish Labour on just 14 points, behind the SNP on 55 and the Conservatives on 22.

Three years ago when Mr Leonard took over as party leader, Scottish Labour was on 25%, just ahead of the Tories.

In the first Holyrood poll in 1999, Labour was the biggest party with 56 seats, gaining 38.8% of the constituency vote. In 2016, it had 24 seats with just 22.6%.

Ahead of the 2015 General Election, Labour had 41 Scottish seats; it now has one.

Recently, the party has fared badly in Scottish local council election votes. Last month in the Clackmannanshire East by-election, its vote collapsed, falling from 20% to just over eight with the Tories polling 51% and the SNP 32%.

Asked if Mr Leonard’s determination to lead Scottish Labour into the May Holyrood elections could destroy it, one senior figure warned: “That is my conclusion. The public polling is showing Labour could be anywhere between 13 and 16% and it’s going down not up; it hasn’t even stabilised. Richard’s personal poll rating shows he is less popular than Boris Johnson in Scotland.”

One Holyrood figure agreed Mr Leonard should go but warned replacing him would be simply “reshuffling the deckchairs on the Titanic,” stressing: “Until we have a credible position on the constitution, nothing will change.”

The MSP condemned whom he called the “Unionist Ultras” and argued for a new constitutional settlement based on full federalism. “We need a positive, sensible programme in which you devolve everything unless there is an overwhelming reason not to.”

Next week, Sir Keir is due to give a keynote speech on his plan for a federal UK when he delivers the John P Mackintosh memorial lecture at Edinburgh University.

However, the great fear among senior Labour figures at Westminster is the threat to the Scottish party could spell disaster for Sir Keir’s chances of ever getting into Downing St at the 2024 General Election.

The UK party leader has made clear how Scotland is vital to his plan to defeat the Tories in four years’ time. Yet, if the party’s standing north of the border weakens rather than strengthens, then another Conservative five-year term at Westminster looks certain.

Despite the pressure for Mr Leonard to go, one Labour insider made clear he was intent on keeping the flame of Corbynism alive.

“The Corbyn cause is dead everywhere else; Richard is the last man standing; he’s the guy at the Alamo. He feels a bit of responsibility for that but on top of all that he and his team genuinely think he is doing a good job and all these problems we face are none of his making.”

In response to the concerns raised, Mr Leonard said: "I will be leading Scottish Labour into the 2021 election on a transformative socialist platform to revive the economy in post-Covid Scotland.

"Scottish Labour members elected me to do this and I will be making the party's case to the electorate ahead of polling day in May, based on policies such as the green new deal to create 130,000 jobs."