Kezia Dugdale, the former Scottish Labour leader, is expected to quit frontline politics after becoming increasingly disillusioned with the party’s stance on Brexit.

It is understood that Dugdale, who headed the Scottish party for two years until suddenly resigning in 2017 after months of tension with UK leader Jeremy Corbyn, has found another job outside politics.

She is expected to confirm her decision within the coming days, the Sunday Times reported, and to formally quit as an MSP at the end of the current Scottish parliament session in June.

Dugdale, a member of Labour’s centrist wing, has made little secret of her unhappiness with Labour’s stance on EU membership and has demanded Corbyn campaigns for a second vote on any Brexit deal.

Dugdale would not comment and her allies refused to be drawn on her resignation.

She has toyed with defecting from Labour to join the Independent Group, now known as Change UK, and is thought privately to be less hostile to Scottish independence than she was as Scottish leader.

Scottish Labour’s youngest leader, she opposed Corbyn’s candidacy when he first stood to be UK party leader in 2015 and in private had very turbulent relationships with his advisers, frequently clashing on domestic policy.

She stunned her supporters at Holyrood by unexpectedly resigning as Scottish leader in August 2017, before inviting further criticism and disciplinary action by becoming a contestant in the ITV reality show I’m a Celebrity … Get Me Out of Here! She lives with her partner Jenny Gilruth, a Scottish National party MSP.

Her decision to quit within weeks of next month’s European elections will dismay Europhile party activists, with many anti-Brexit voters now flocking to the SNP, which under Nicola Sturgeon has championed the remain cause in Scotland, at Labour’s expense.

Dugdale is a close friend and ally of Ian Murray, the Labour MP for Edinburgh South, who has emerged as Labour’s leading spokesman in Scotland for the People’s Vote campaign.

The latest opinion polls suggest Scottish Labour is languishing well behind the SNP in the European elections. A YouGov poll for the Times this weekend put the SNP on 40% and poised to take at least three of Scotland’s six European parliament seats.

Labour, however, which won two seats at the last European elections after taking 27% of first preference votes, is due to hold only one next month with YouGov showing it now at 20%.

Dugdale was elected as an MSP for the Lothians on the regional list, under Holyrood’s proportional voting system. Since her seat is not based on a first past the post contest, her departure will not trigger a byelection.

The next Labour candidate on that list is Sarah Boyack, a former Labour MSP and minister, who is also close to the party’s centrists. It is not known whether Boyack will opt to return to Holyrood.