Revised plans to slash the number of MPs, which could help Tories to an outright Commons majority, will be unveiled next week.
If original boundary commission proposals reducing the total by 50 to 600 had been in force at the last General Election, Conservatives would have had a four-seat overall advantage, leading election experts Professors Colin Rallings and Michael Thrasher of Plymouth University calculate.
Their estimated line-up is: C 302 (including the Speaker) - down five from the actual result, Lab 227 - down 31, Lib Dems 47 - down 10, SNP six - no change, Plaid Cymru two - down one, Green nil, down one, Northern Ireland parties 16 - down two.
The Boundary Commissions for England and Northern Ireland, after wide-ranging consultations, will on October 16 publish amendments to their initial scheme.
They will then be open to a final round of representations before submitting plans for Commons approval in October next year.
This may not be given as Liberal Democrats have said they will vote against the proposals after the scrapping of Lords reform following backbench Tory objections.
The boundary commissions are required to ensure no constituency has an electorate smaller than 72,810 or more than 80,473.
An exception is the Isle of Wight which will have two constituencies instead of one.
Also in Scotland, where amendments have already been published, the island constituencies of Na h-Eileanan an Iar and Orkney and Shetland have been allowed to remain below the quota.
The Boundary Commission for Wales publishes its revised proposals on October 24.