Government plans to offer councils cash rewards for exceeding their house building targets could lead to more unwanted back garden development in affluent Birmingham suburbs.

Local authorities stand to receive annual grants worth millions of pounds on the basis of the number of planning permissions they approve, if proposals in a Department for Communities and Local Government consultation paper are accepted by Ministers.

Councils failing to meet targets would be "fined" by having grants taken away from them.

The idea was dismissed by Birmingham City Council's cabinet member for regeneration, Ken Hardeman, who warned that any attempt to increase the number of new homes already planned in the city would lead to pressure for development in the large back gardens of Victorian and Edwardian properties typically found in Moseley, Kings Heath, Edgbaston and Sutton Coldfield.

The proposals also sparked fierce reaction from countryside campaigners, with the Campaign to Protect Rural England describing the payments as a "blatant bribe" that would take the country back to the 1960s when councils were encouraged to approve estates of cheap, sub-standard housing on green field sites.

Birmingham council leaders are already involved in a campaign to persuade the Government to give more protection to backgarden sites which presently are classified as brownfield land, ranking them alongside former industrial sites.

Earlier this year the council warned of builders "cold calling", knocking on doors in areas like Sutton Coldfield to persuade householders to sell back gardens development.

Coun Hardeman (Con Brandwood) admitted Birmingham was already struggling to meet its target of 71,000 new homes by 2026. The council would like to see most of the properties built on derelict former industrial land, but sites are few and far between.

Coun Hardeman added: "We are trying to stop back garden development but we do have difficulty in identifying sufficient brownfield sites. If we are given additional targets than the tensions will increase.

"There could be more pressure on us to allow infilling and we do not want that."

The DCLG consultation paper makes it clear there would be no ceiling on the money councils could make if they exceed the target for new homes set by Secretary of State for Communities and Local Government Ruth Kelly.

The total national planning grant for 2007/08 will be £120 million.

Gerald Kells, West Midlands spokesman for the Campaign to Protect Rural England, said: "When you get to the shires there is a great danger in this. "We have all seen housing developments that are out of keeping and generally not of a good standard."