Labour in Scotland may “never recover” after posting the worst results in the party’s history in the European elections, two of its MPs have warned.

Ian Murray and Martin Whitfield said Scottish voters had “delivered an utterly damning verdict” on the party – which lost its two MEPs from Scotland and fell from second to fifth in the polling.

David Martin had been the UK’s longest serving MEP, having spent 35 years in Brussels, before being voted out of office – blaming Labour’s failure to take a clear stand on the crucial issue of Brexit for the result.

Mr Martin tweeted: “We lost not because of lack of effort but lack of clear message.”

Speaking on BBC Radio Scotland, Mr Martin said there must now be a shift in Labour’s position on Brexit and establish itself as a pro-European party.

The former Scottish Labour MEP added that the party’s leader, Jeremy Corbyn, had become “stuck in limbo” on the question of the UK’s EU membership.

Mr Martin said: “I kind of understand the position that Jeremy Corbyn tried to take.

“He’s the leader of one of the two major parties in the United Kingdom, we had a referendum and that referendum said we should leave the European Union, so he felt an obligation to try and deliver on that.

“It’s become clear that there is no easy way, in fact I would say it’s impossible, to deliver on what the people have asked for.

“But he was stuck in this limbo of knowing the damage a hard Brexit would do to the country, but, at the same time, feeling an obligation to respect the outcome of a national referendum.”

Mr Murray, the Edinburgh South MP and his East Lothian colleague Mr Whitfield, insisted the results must act as a “wake up call” for Jeremy Corbyn and the Scottish Labour leader Richard Leonard.

Writing in the Edinburgh Evening News, the two MPs said: “The European election results are by far the worst results in Scottish Labour’s long and proud history.

“There is no way to sugar-coat this – the people of Scotland have delivered an utterly damning verdict.”

Voters had told them that “they felt they had no choice other than to back explicitly pro-remain parties instead of the Labour Party,” they added.

And while they said it was “devastating” Mr Martin would no longer represent Scotland in the European Parliament they insisted he could still “hold his head high”.

The MPs insisted: “The blame for the worst result in Scottish Labour’s history lies squarely with our party’s leadership.

“This was an election campaign about the biggest issue facing our generation: Brexit. And yet we walked away from that battlefield, offering nothing but ambiguity on an issue that will determine the future of our country.”

Labour came sixth in the Edinburgh City Council area, behind the SNP, the Conservatives, the Liberal Democrats, the Greens and Nigel Farage’s newly formed Brexit Party.

But the MPs claimed if the party had had “a clear commitment to fight to remain in the EU” it could have won in the capital and areas like East Lothian.

“Instead, we were decimated,” they said.

“It is official Labour Party policy to support a People’s Vote as a way out of this catastrophic mess, yet Jeremy Corbyn snubbed our membership and refused to embrace it. As a result he personally handed victory to Nigel Farage.”

They also hit out at Scottish Labour, saying the party north of the border “could have chosen very different path”.

They continued: “This was Jeremy Corbyn and Richard Leonard’s manifesto, their message, their decision to ignore the membership and what voters were saying to us. It was their election campaign and their mess.

“They stuck their heads in the Brexit sand because they can’t lead. We have paid the price for their failure and we have been wiped off the electoral map.”

The two MPs added: “These results must now act an urgent wake-up call for Richard Leonard, deputy leader Lesley Laird and campaigns manager Neil Findlay.

“If there is to be any hope of recovery, Scottish Labour must become a passionate, relentless, and vocal voice for a final say on Brexit. There can be no ambiguity – any Brexit deal simply must be put to the public.

“We must commit to remaining in the EU, and campaign for this if there is a snap general election.

“Scottish Labour can lead the wider Labour movement on this, and should have been doing so for many months.”

Mr Leonard said that he was “personally extremely sad” Mr Martin had lost his seat.

The Scottish Labour leader said: “Labour was the only party fighting this election to bring the country back together.

“The divisions caused by the competing nationalisms of the UK and Scottish Governments continue to be a distraction from both of their failures.”

He insisted the party had put “everything into our campaign and were confident that our focus on jobs and a fair wage, schools and community would resonate with voters”.

And he said he would “continue to put all my efforts into rebuilding the party for the many, not the few”.

Scottish Labour MP Ged Killen paid tribute to Mr Martin and said that the loss was no fault of his and no reflection of his “extraordinary” record as an MEP.

Mr Killen said: “This election felt like watching a slow motion car crash. The outcome was entirely avoidable and incredibly frustrating for people like me who have consistently argued for a final say referendum with Labour campaigning to remain.

“Instead, we have tried and failed to be all things to all people and it has left voters confused about what we stand for.

“It is crucial that we heal divisions in the country, but we can only do that by being straight with people and staying true to our values.

“Scottish Labour now has a choice to make: we can start listening and respond with the courage of our convictions, or we can continue to stick our heads in the sand and become an irrelevance in Scotland.”

Meanwhile, the SNP’s Westminster leader Ian Blackford said the party would give its support to forming a progressive alliance with Labour, but stated that doing so would be contingent on allowing another referendum on Scottish referendum.

Mr Blackford said: “In our manifesto in 2015 and 2017, we said that we would form a progressive alliance if it was possible to do that.

“But what we are saying, quite specifically, is that we won the election to the Scottish Parliament in 2016 on a manifesto commitment that if there was a change of circumstances, that Scotland had the right to call a referendum.

“We won that election to the Scottish Parliament in 2016, there is a pro-independence majority in the Scottish Parliament. I’d simply say to Westminster that you have to respect the sovereignty of the people of Scotland.”