England will lose even more MPs than previously expected when the electoral map is redrawn for the 2020 general election, the Boundary Commission has revealed.
It has begun a review that will see the number cut from 533 to 501 as part of a wider process by bodies in each part of the UK to slash the overall number of Commons seats from 650 to 600.
That is one fewer still for England than was proposed in a 2013 review, which was halted by the Liberal Democrats in a spat with their then Conservative coalition colleagues.
Changing population patterns mean that seat will now go to Scotland.
Regions losing one more seat than previously anticipated are the West Midlands, which is due to drop from 59 to 53, and the North East which will have 25 rather than the present 29.
But the Eastern region will see its representation cut by only one altogether, from 58 to 57 - one more than the 56 suggested in the last review.
The changes are expected to benefit the Conservatives by as many as 20 seats, sparking accusations of gerrymandering by rival parties.
Official figures for the calculations have shown a dramatic slump in electoral rolls, especially among young voters and in poorer areas, which critics blame partly on a Government move to accelerate the switch to a new registration system.
Shadow minister Gloria De Piero said: "The Government are shamelessly taking this as an opportunity to redraw constituency boundaries based on an electorate that is far lower than it should be.
"This is another example of David Cameron and the Conservative Party trying to rig the system for their own political ends."
To diminish the ever-widening gap between the numbers of voters electing MPs, each of the new constituencies must contain between 71,031 and 78,507 registered voters - based on the December 2015 rolls.
The exception is the Isle of Wight whose 105,448 voters will be split into two constituencies.
The Office for National Statistics found that the number on the register was down almost 600,000 on the previous year.
MPs will find out if their seats are likely to disappear when detailed proposals are set out in September before a 12-week consultation process and then a detailed review.
Final recommendations must be submitted to Parliament in September 2018.
Sam Hartley, Secretary to the Commission, said: "Parliament has set us strict rules on reducing the number of constituencies and bringing greater equality of electorate size between the new constituencies - these new rules mean that there is likely to be a large degree of change across the country.
"Once we publish our initial proposals in the autumn, we will need the help of residents in all regions to ensure that our proposals take account of local ties and best reflect the geography on the ground.
"Everyone's views will help us recommend a well-considered and practical set of constituency boundaries in England."
England's total electorate is 37,399,942.
The full breakdown of constituency numbers by region is
Eastern 57 (58) Electorate: 4,242,266
East Midlands 44 (46) Electorate: 3,275,046
London 68 (73) Electorate: 5,118,884
North East 25 (29) Electorate: 1,874,396
North West 68 (75) Electorate: 5,074,302
South East 81 (83) Electorate: 6,067,475 (Excluding the Isle of Wight)
South West 53 (55) Electorate: 3,930,770
West Midlands 53 (59) Electorate: 3,989,320
Yorkshire and the Humber 50 (54) Electorate: 3,722,035
John Penrose, Minister for Constitutional Reform, said: "Equalising the size of constituencies in the boundary review means everyone's vote will carry equal weight.
"If we let some constituencies stay smaller than others, voters will have more power in them than people in bigger ones. And the boundaries would be based on data that's 20 years out of date.
"That can't be fair or right."