Psephologist Robert Waller analysed the marginal seats and boundary changes in every UK region for Total Politics in a long-running series from December 2008 onwards. With the election now just oone week away, we will look back at his findings in the run-up to the election. Today we look at the East Midlands. You can read the full article here.

Victories in marginals in the East Midlands — here defined as Northamptonshire, Leicestershire and Lincolnshire - have bolstered Labour in recent elections. However there is bad news here for the government.

Northamptonshire has the highest proportion of marginal seats in the country. In 2005, six out of its seven constituencies could fairly be placed in the category of those critical to the choice of government. This year it gains one new seat — Northamptonshire South — which will be safely Conservative for Tory A-lister Andrea Leadsom.

The creation of the news seat has had a knock on effect for the urban seat of Northampton South where notional results for 2005 suggest that Labour would have won here. However recent national polls suggest Brian Binley will hold on to it for the Tories. They also look to be secure in Kettering and Wellingborough where they will benefit from national Tory strength and the first term incumbency effect of two active MPs, neither implicated in the expenses scandal.

This suggests that Labour are likely to lose all their seats in Northamptonshire. Louise Bagshawe, the ‘chick-lit’ novelist, only needs a two per cent swing to take Corby and Sally Keeble will lose it to Michael Ellis on a swing of less than five per cent.

The Conservatives must take two seats in Leicestershire if they are to form a government. A swing of two per cent will see Labour’s Andy Reed dislodged in Loughborough while a more challenging swing of five per cent is needed by Andrew Bridgen in Leicestershire North West.

The Lib Dems have two targets in Leicestershire — Harborough and Leicester South - though they are unlikely to take them. Labour’s vote in Leicester is holding up better than anywhere else in Britain. The seats held by Keith Vaz (East) and Patricia Hewitt’s replacement Liz Kendle (West) are also likely to remain safe.

The Conservatives won six of the seven seats in Lincolnshire easily in 2005 and look to take the rural, affluent Grantham and Stamford again this time. Represented by a Labour MP since 2007 when Quentin Davies defected, it looks to be a safe win for Nick Boles. The other seat that might change hands is Lincoln where Karl McCartney will benefit from boundary changes in his bid to oust Gillian Merron.

There seems a good chance that the three East Midland counties will return a full slate of Conservative MPs at the next election, with the exception of the three probable Labour seats in Leicester. This is very bad news for the government who have relied on victories here since 1997.