Being in power is a new experience for most Liberal Democrats – but it is proving toxic to their Midland supporters, if party membership figures are anything to go by.

Accounts produced by local parties show that membership has plummeted by nearly a quarter in some constituencies. And Conservatives have also suffered a dramatic decline in membership in parts of the country.

The number of activists deserting the coalition parties is revealed in accounts produced by the parties themselves and published by the Electoral Commission. They show membership levels at the end of 2011, after 18 months in power, compared to those at the end of 2010.

Not every local party sent full copies of their accounts to the Electoral Commission, which means they give only a partial account of the picture across the country.

But figures for Solihull and Meriden Liberal Democrats show that membership was down to 188 at the end of 2011 – from 246 at the end of 2010. That’s a fall of 24 per cent, nearly a quarter.

The accounts state that “the main activity of the local party has been to support Lorely Burt MP and the local councillors with increasing work in all aspects of constituency work and electioneering, and to support our solitary MEP Liz Lynne to hold her seat in the European Parliament.”

Ms Burt is the MP for Solihull, elected in a surprise win over the Tory incumbent in 2005.

Other Lib Dem seats have also seen a decline in membership, but not always so dramatically. In Westmorland and Lonsdale, where the MP is Lib Dem President Tim Farron, membership fell from 454 to 399, down by 12 per cent. Party membership in Yeovil, the seat once held by former party leader Paddy Ashdown, fell from 483 to 400, down by 17 per cent.