Boundary changes mean more marginal seats in the West

The political map of the West Country is changing - even before the General Election results are known.

Two new constituencies have been created and many smaller boundary changes made across the area, making some seats more marginal.

Political geographer Ron Johnston said it is in the marginals that the General Election will be won.

"Basically, this election is going to be decided by about 200,000 people in the marginal constituencies," he said.

The boundaries have shifted for two main reasons.

The Boundary Commission, an independent organisation which lays the changes before Parliament, likes to keep constituencies to about 70,000 people.

It also aims to keep whole council wards within constituencies.

The most noticeable change in the West Country is the creation of two new constituencies: Chippenham, and Filton & Bradley Stoke, known as FABS.

'Notional results'

FABS is a marginal three-way seat between the main parties.

The changes also mean that Bristol North West, which was once comfortably Labour, could now go one of three ways. The constituency has adopted part of Bristol West but has lost land to FABS.

Kingswood has become more marginal, shedding a number of wards to Bristol East.

And Bristol West exchanges Henleaze and Westbury on Trym for Lawrence Hill and Easton.

Small boundary changes can make all the difference and this is particularly relevant in North East Somerset.

It is made up largely of the old Wansdyke seat, which has returned a Labour MP - Dan Norris - in every election since the New Labour landslide of 1997.

His majority at the last election was 1,839 - or 3.6%.

But if you look at the seat's "notional results", it is Conservative - by just over 200 votes.

Notional results are not a prediction of what will happen. Rather, polling experts have estimated the votes for each party in each seat where the boundaries have changed, as if it had been fought in the 2005 general election, and delivered these notional results.

Ron Johnston, Professor of Geographical Sciences at the University of Bristol, said: "Even if you just move a couple of wards around you can make one constituency much more marginal or less marginal.

"As we know, the marginals is where it all happens.

"Basically this election is going to be decided not by all 43 million of us, but by about 200,000 people in the marginal constituencies. The rest of the country doesn't matter."