Conservative MPs will meet today to thrash out the implications of a proposed shake-up in the region's electoral boundaries - including controversial moves for a new seat straddling Norfolk and Cambridgeshire.

Although the number of MPs in Norfolk will not be changed by the Boundary Commission's proposals and will remain at nine, the creation of a new seat crossing the border of Norfolk and Cambridgeshire paves the way for potential conflict between Conservative MPs.

That is because the new Wisbech and Downham Market constituency takes in part of the South West Norfolk seat currently held by Elizabeth Truss and some of the North East Cambridgeshire seat held by Stephen Barclay - both constituencies which would disappear under the proposals.

The Boundary Commission's review, which was ordered by the government, is designed to cull the number of MPs by 50 to 600 and to iron out discrepancies in constituency electorates.

Rules state that every constituency in England, bar two on the Isle of Wight, must have an electorate of between 72,810 and 80,473 - 5pc either side of the electoral quota of 76,641.

The Boundary Commission says it needed to put forward the cross-border constituency to make that happen because the number of electors in Norfolk (651,119) meant it could not allocate a whole number of constituencies to the county.

They said allocating eight of the largest permissible constituencies would need an electorate of 643,784, while allocating nine of the smallest constituencies would need 655,290 electors.

Because Cambridgeshire was in a similar boat it made sense to group the counties, the commission said, hence the proposed cross-border Wisbech and Downham Market constituency.

While MPs were reluctant to publicly discuss the implications of that cross-border constituency, it creates a scenario where Ms Truss could be vying with fellow Conservative Mr Barclay for that new seat.

The situation is further complicated because the Mid Norfolk constituency, currently held by George Freeman. will also disappear.

The commission has put forward a new Thetford and Swaffham constituency, which would be an amalgamation of parts of Mid Norfolk and Ms Truss's South West Norfolk constituency, including Thetford, where her constituency office is based.

Other parts of South West Norfolk - including Wiggenhall, Tilney St Lawrence and Watlington - would be absorbed into a newly named King's Lynn constituency, which would also take in all of Henry Bellingham's existing North West Norfolk constituency.

Ms Truss, who lives in Downham Market, was not commenting last night, but it is understood Conservative MPs from across the region will be discussing the implications of the shake-up at a meeting today.

Meanwhile, Mr Barclay, potentially Ms Truss's rival for the new Wisbech and Downham Market constituency, gave a diplomatic reaction to the proposed changes, which would come into effect for the general election in 2015.

Mr Barclay, who lives in March, which would be part of that new constituency, said: 'We need to take a bit of time to digest the changes. We need to look at them and understand them. Around 56pc of the seat comes from my existing constituency and 43pc from South West Norfolk, so it is a new seat.

'It's very early days and people need to take their time and look at it in more detail. It's a change not just for MPs, but for the constituents as well.

'Some will not care in the slightest and life for them will carry on as normal, but there will be those who will be concerned about it, especially if there have been a number of successive changes.'

The report by the Boundary Commission justifies the proposal by pointing out: 'There are good road links along the A1101 and A1122 between the two towns named in the constituency.'

Elswhere in Norfolk, the Boundary Commission said changes need to be hmade to Norwich North, Great Yarmouth and North Norfolk to bring them up to within 5pc of the electoral quota.

To enable that to happen, Dereham would become part of a revamped Broadland and Dereham constituency, while Taverham North and South, plus Drayton North and South would leave Broadland to become part of Norwich North.

Chloe Smith, Norwich North MP, said: 'These are initial proposals and are subject to several rounds of further consultation, both publicly and in parliament.

'They would not take effect until 2015 in any case. My view is that I look forward to contunuing to serve Norwich North if I am elected to do so.'

Elsewhere Fakenham would switch to North Norfolk, having only last year been moved into Broadland, while three wards currently in North Norfolk - Stalham and Sutton, Waterside and Waxham - would move to an extended Great Yarmouth constituency. Brandon Lewis, Conservative MP for Great Yarmouth, said: 'It's a bit early to say much and it's about to go out to consultation.

'But my view is that the government's principle of trying to get fair and equal constituencies is the right way to go.'

Norwich South would be the only constituency to remain unchanged, although South Norfolk would see only minor changes.

In Suffolk, there is less change, with Waveney, Suffolk Coastal, Central Suffolk and North Ipswich unchanged, but the electorate for Bury St Edmunds reduced by moving four wards out of it. Newmarket would be included in a new Newmarket and Ely constituency.

The public can have their say on the proposed changes during a 12-week consultation which will end on December 5. Visit www.consultation.boundarycommissionforengland.independent.gov.uk to see the proposals.

A two-day public hearing about the changes will be held at City Hall in Norwich from 11am until 8pm on Thursday, November 3 and from 9am until 5pm on Friday, November 4.