KEZIA Dugdale has claimed she quit as Scottish Labour leader last year over unhappiness with the UK party’s position on Brexit.

The Lothians MSP told a private meeting of Labour colleagues that Jeremy Corbyn's stance on leaving the European Union – based on a perceived failure to fight a hard Brexit – was one of the factors behind her departure.

However, a senior party source said Dugdale’s claim was a “breathtaking attempt at rewriting history” and said she was “softening the ground” for leaving the party.

A spokesperson for Dugdale said: “Kez’s views on Brexit are long-standing and well known. She is passionate about preventing a hard Brexit and protecting jobs, the economy and workers’ rights. The Labour Party is the best vehicle for stopping a destructive Brexit in its tracks and we must all work together to stop the Tories from taking us down such a ruinous path.”

Labour has struggled to adopt an agreed position on Brexit due to the politically-difficult task of pleasing both pro-remain party members and voters who backed leave.

Corbyn, a lifelong Eurosceptic who said he voted remain, has backed continued membership of the single market, but only on a temporary basis.

Senior figures in the party want him to either back the UK staying in the single market permanently, or support a second referendum in the hope of overturning the result.

The row has spread to Scottish Labour, where new leader Richard Leonard has endorsed the Corbyn position and resisted demands to adopt a separate policy.

A summit was staged last week for Labour MSPs to debate Brexit and speak freely about the stance they believe the Scottish party should take.

Neil Findlay MSP, who is Leonard’s Brexit spokesman, is said to have made a presentation and contributions were made by colleagues.

An insider said Dugdale, who walked away as leader in August, was one of a number of MSPs who criticised the party’s position and called for a rethink.

She is said to have reiterated her call for a referendum on the final Brexit proposal and claimed that UK Labour’s position was a reason behind her decision to quit.

However, party colleagues are sceptical of Dugdale’s retrospective account of her abrupt departure.

Dugdale’s resignation statement made no reference to Brexit being a trigger and she instead suggested the death of friend Gordon Aikman had been a factor.

“Earlier this year I lost a dear friend who taught me a lot about how to live. His terminal illness forced him to identify what he really wanted from life, how to make the most of it and how to make a difference. He taught me how precious and short life was and never to waste a moment,” she wrote.

The statement also made a general reference to political events: “Emerging from the challenging times following the 2014 referendum, and the 2015 UK election, we now have a solid platform on which to build towards success, and government. I have given the task of achieving this all that I have.”

One party source said: “The real reason Kez quit is that she couldn’t be bothered any more. She wanted to spend more time with her partner and enjoy life. It was nothing to do with Labour’s position on Brexit.”

Another insider said: “It’s a breathtaking attempt at rewriting history. My view is that she is softening the ground for leaving us and sitting as an independent MSP."

However, a source close to Dugdale said it was “categorically” not the case she would leave the party.

Since quitting, Dugdale has taken aim at Corbyn’s performance during the EU referendum campaign.

“I also blame my party, the Labour Party, for a totally lazy and lacklustre remain campaign that got us here,” she wrote in November.

A Scottish Conservative spokesman said: “Once again we see Scottish Labour at sixes and sevens over Brexit. The party is in a state of disarray and this meeting shows that there are still deep divisions amongst the leadership and their elected members.”