The Fabian Society claims that Labour is “too weak” to win a general election alone and should consider working with rival parties.
General secretary Andrew Harrop said there had been a “complete meltdown” of support in Scotland, and his study also cited party leader Jeremy Corbyn’s unpopularity and a “muffled” approach to Brexit.
A Fabian report warns the party was on course to win fewer than 200 seats for the first time since 1935 – it currently has 231. Based on current opinion polls, the total could be as low as 140 MPs because Labour traditionally does worse than its mid-term polling suggests.
Harrop said it was a “pretty terrifying thought” for most Labour supporters, but the report claimed Labour could gain 30 extra seats by aligning with centre-left parties in the next election.
“Labour needs to prepare itself to work in partnership, in an age of quasi-federal, multi-party politics,” the Fabian report added.
In this scenario, Labour would remain by far the largest opposition party, would not face oblivion and would be able to rebuild.
The report accused the parliamentary Labour party of being “barely audible” compared with the “sound and fury” of the first year of Mr Corbyn’s leadership, adding: “The Corbynite left has won the big internal battles but it seems to have no roadmap for winning back lost voters.”
Corbyn’s spokesman said: “Labour under Jeremy Corbyn will be taking its case to every part of Britain in the coming months with a radical policy platform.”
Earlier, Unite boss Len McCluskey appeared to suggest that Corbyn would step down if the party’s poll ratings fail to improve, but he later tweeted his “full support” for the Leader, describing him as a “genuine, decent man fighting for a fairer Britain”.