Families face £1,000 'bedroom tax' before councils give permission for home improvements

The charges - dubbed a 'bedroom tax' - must be paid before town halls give permission for home improvements.

The officials behind the scheme justify it by saying the money is needed to maintain public transport and roads.

Councils are charging homeowners who want to build extensions £1,000 per room to 'maintain public transport and roads'

But last night critics said it is unfair to further penalise homeowners already struggling under soaring council tax bills.

The charges were trialled in the village of Purbeck in Dorset and may be copied by cash-strapped councils across Britain.

The 'bedroom tax' has been brought in under laws which allow councils to ask for money from developers such as supermarkets in return for granting them planning permission.

In Purbeck, which is run by a minority Tory group, those building home extensions are considered developers and will be asked for £993 for each room that can be used as a bedroom.

An administration fee of at least £50 must also be paid.

The charges follow delays to the Government's revaluation of properties for council tax, which was put on hold three years ago.

The revaluation would have pushed up rates for those who have improved or extended their home.

Jim Knight, Labour MP for South Dorset, said: 'It's unfair for residents-because it just looks to me and to the people I represent as a money-making scheme for the council rather than it being something that's fair or reasonable.'

Tory local government spokesman Eric Pickles said: 'At a time when families are being punished with punitive stamp duty if they move house, it is unfair to hit them with taxes if they stay put and want to extend their home.'

Purbeck District Council planning manager Alan Davies said: 'We needed to raise an extra £20million to pay for a £30million package of transport improvements to cope with any future developments.

'The alternative is to refuse all planning applications or bring in a congestion charge which the council decided wasn't fair.'

The system - given full approval in April - has raised £90,000 for the council since the beginning of 2007.

Around two million homeowners are thought to undertake home improvements of some kind each year, although only a minority need planning permission.

A spokesman for the Department of Communities and Local Government said new laws to tax developers in return for planning permission will exempt householders.