Some so-called Labour "safe seats" with majorities of more than 10,000 votes are under threat at the general election, two of the party's MP candidates have warned.
The unnamed politicians told Bloomberg that as many as 120 constituencies could fall on 8 June as internal party polling is reportedly indicating a rout.
"Both lawmakers declined to be identified discussing internal party matters," the publication said. The claims come after a public poll bounce for Labour following the leak of a draft copy of the party's election manifesto.
The policy document committed a Labour government to renationalising the railways, Royal Mail and energy firm.
The shadow cabinet and Labour's ruling body, the National Executive Committee, met on Friday (12 May) to agree on the commitments.
Party leader Jeremy Corbyn said the grandees "unanimously" backed the document, with a few unannounced amendments. The full and official manifesto will be published on Tuesday (16 May).
The latest ComRes poll, of more than 2,000 people between 10 and 12 May, put the Conservatives on 48% (-2), Labour on 30% (+5), the Liberal Democrats on 10% (-2) and Ukip on 5% (-2).
Theresa May has consistently visited Labour-held seats across the the course of the election campaign, suggesting that her party's internal polling is pointing towards a Conservative majority.
The Tory premier even travelled to the North East of England, usually seen as Labour heartland, on Friday. The Conservatives could take seats in the region such as Hartlepool, Darlington, Bishop Auckland and Tynemouth from Labour on 8 June.
Labour had responded to a request for comment at the time of publication.