NICOLA Sturgeon has savaged Scottish Labour leader Richard Leonard's "feeble" stance on Brexit and challenged him to make clear his party's position on Europe.

Sturgeon said Leonard was betraying Scots who overwhelmingly voted Remain in 2016. Both UK Labour leader Jeremey Corbyn and Leonard are under growing pressure to back cross party moves to keep the UK in the single market.

Speaking exclusively to the Sunday Herald, she challenged Leonard to make his position clear on Brexit. The Labour Party is facing increasing criticism over what is seen as its confused position on the European Union.

READ MORE: Richard Leonard under pressure over bid by Labour centrists to dump left-wingers from party 

Sturgeon accused Leonard of "doing literally nothing to fight the Tories’ chaotic Brexit plans". The First Minister also said Leonard was "effectively backing the Tories’ extreme Brexit plans" with his approach.

She said Labour at Holyrood and Westminster was mired in confusion and chaos over its approach to Brexit.

Leonard has mirrored the position held by Jeremy Corbyn of honouring the outcome of the 2016 referendum, but backing a deal that allows single market access. Both Scottish and UK Labour have refused to support full membership of the single market and customs union. Sturgeon blasted the stance as "utterly bizarre and inexcusable".

She accused Leonard, who was recently elected as leader on a left-wing platform, of adopting a similar Brexit position to the Tories.

Speaking exclusively to the Sunday Herald, she said: "Scottish Labour’s position – in line with that of their London bosses – is utterly bizarre and inexcusable. They are effectively backing the Tories’ extreme Brexit plans, which threaten many thousands of Scottish jobs and risk doing huge damage to our economy and society."

Meanwhile, confusion over the party's position on a "soft Brexit" has deepened with a poll suggesting that Labour supporters are unsure of the party’s position.

Nearly a quarter of those surveyed by YouGov said they thought Labour was completely against Brexit, a third thought it was on the fence, and a tenth were unsure. A separate ICM survey showed that voters support the idea of holding a second EU referendum by a 16-point margin.

The poll found 47 per cent of people would favour having a final say on Brexit once the terms of the UK’s departure are known, while 34 per cent oppose that.

Paul Hutcheon: Richard Leonard is a goldfish swimming with piranhas

In a sign of escalating tensions in the party over the Europe, Tony Blair said Corbyn had a "cake and eat it" approach to EU withdrawal.

The former PM said that Corbyn’s frontbench – including shadow chancellor John McDonnell had made contradictory remarks about Brexit.

Blair said that if Britain does leave the EU, then Labour’s “timidity” will bear responsibility alongside Tory right-wingers who have been pushing for Brexit.

Speaking earlier this month, Blair said: "Here Labour has its own ‘cake and eat it’ phrases. The Shadow Chancellor [Mr McDonnell] says we will not be in ‘the’ single market but ‘a’ single market. The shadow industry minister [Barry Gardiner] talks of keeping the benefits of the customs union agreements but still being free to negotiate our own trade deals. This is confusing terrain on which to fight.”

Senior pro-EU Labour MP Chuka Umunna added that his party was undecided on whether to support permanent single market membership after Brexit, while stating his own support for a soft Brexit. “I am very clear. I think we should be arguing for us to stay in the single market permanently," Umunna said.

Last night, with Corbyn and Leonard both under pressure over the confusion surrounding Labour's position on Brexit, Sturgeon stepped up her own criticism of the Scottish Labour leader.

The First Minister challenged Leonard to make clear his position on Brexit to Scottish voters. Sturgeon said: “Labour have already taken a hit in the polls as people realise they are doing literally nothing to fight the Tories’ chaotic Brexit plans.

“And that trend is only likely to grow as more and more people across Scotland, including Labour supporters who oppose Brexit, see just how feeble the party is on the biggest single issue facing the country.”

Scottish Labour under Leonard has abandoned the pro-single market policy held by the party under Kezia Dugdale's leadership. Leonard decisively defeated Anas Sarwar in a bitter Scottish Labour leadership contest last year. One of Sarwar's flagship campaign policies was backing for single market membership.

Last night, a Scottish Labour spokesperson said Leonard backed a Brexit deal that would protect jobs and the living standards of working class Scots.

The party spokesperson said: “The Tories’ are fixated on a bargain basement Brexit that is putting jobs and investment at risk. Labour will deliver a jobs-first Brexit that protects our industries and workers' rights, as part of our plan to create a country that works for the many, not the few."

READ MORE: Richard Leonard under pressure over bid by Labour centrists to dump left-wingers from party 

The Scottish Labour spokesperson also hit back at Sturgeon and accused her of using Brexit to agitate for independence - despite her not mentioning independence in her comments.

He said: “This is typical posturing from Nicola Sturgeon, which is as much about opportunistically pursuing her own constitutional obsession and using Brexit as the means to achieve that."