Wigan borough’s constituency Labour parties will find out next month if they are facing boundary changes ahead of the 2020 general election.
Review proposals are set to be released in September but analysis of the likely impact has found a vast majority of Labour seats will be affected in some way.
This could mean up to 30 Labour seats disappearing altogether, according to a review by Tory peer Lord Hayward.
The changes, pushed through by former Prime Minister David Cameron, propose a cut the number of MPs by 50 to 600 to create seats with similar numbers of constituents.
More Labour seats are thought to be under threat with the review suggesting the party is currently over-represented.
This has led to claims of “gerrymandering” from those within Jeremy Corbyn’s party.
Previous boundary change proposals in 2010 would have seen the Leigh constituency carved up along with neighbouring Salford and Eccles.
Those plans were ditched but speculation remains that Leigh could be significantly impacted in the current plans.
Lord Hayward’s figures suggest that of the 50 seats that disappear, the Conservatives will lose between 10 to 15, which is 4.5 per cent of their total but Labour is on track to lose between 25 and 30, some 13 per cent of their current representation.
Some constituencies could turn from safe Labour seats to marginal ones, it adds.
The impact on Labour could be especially painful, as critics of Jeremy Corbyn face the prospect of reselection processes for the revised constituencies.
Labour’s work on the boundary review has been led by Dame Rosie Winterton, the chief whip, and her spokesman said the analysis was fresh evidence the policy was a “partisan” move to benefit the Tories.
The Opposition urged Prime Minister Theresa May to abandon the plan, arguing that the imminent loss of 73 MEPs as a result of Brexit would heap extra work on MPs.
Labour also highlighted the surge in numbers on the electoral roll as a result of the EU referendum, resulting in an extra two million registered voters who were not factored in to the boundary review.
A spokesperson for Dame Rosie said: “The Tories’ plan to arbitrarily reduce the number of elected Members of Parliament by 50 had always been under the guise of reducing the cost of politics, even whilst they continued to cram the Lords at taxpayers’ expense.