A Government minister has paved the way for Bristol's green belt to be bulldozed.

Iain Wright admitted that the move would mean developers could cherry-pick beauty spots to build on.

The junior housing minister told a Parliamentary debate that rules directing that brownfield sites must be chosen before protected green space is even looked at were "rigid and old fashioned".

If the green belt's protection is removed, councils will only have limited powers to stop builders choosing the most attractive and lucrative countryside locations to build on, while industrial sites are left languishing.

Mr Wright's words yesterday came as a bitter blow to local politicians and campaigners, who made impassioned pleas in an hour-and-a-half Parliamentary debate on the Regional Spatial Strategy.

The massive planning and transport blueprint calls for tens of thousands of homes to be built on formerly protected land.

Northavon MP Steve Webb, who called for the debate, said: "I'm shocked. This is devastating.

"He claimed to be committed to the green belt but they are removing the protection for it."

Dozens of protesters turned up to listen to the debate at Westminster Hall before handing in petitions with thousands of signatures at Downing Street.

Debbie Nicholls, of Dundry Residents' Action Group, said: "I have never seen so many MPs batting from the same wicket, but when the minister summed up, it was as though he had ignored everything that had been said.

"We've handed in a petition to Downing Street and will not give up the fight."

In a frank discussion that saw furious MPs of all political allegiances band together, the junior housing minister was told the consultation process set up to allow members of the public to have their say on the plans was "a farce".

Mr Webb told MPs he had phoned the office running the internet site for the consultation to ask why it had not been updated, only to be told it was "because Gary is on holiday" – referring to the member of staff responsible.

He also listed the problems encountered by residents who had tried to comment on the scheme but had given up after being overwhelmed by the glitches in the system.

"Either do it properly, or don't do it at all. If you want people to respond, make it easy," he said.

"The green belt is vital, especially in areas that have seen rapid urbanisation.

"This isn't about country-dwellers throwing up barriers. People in Bristol want the green belt kept too."

Roger Berry, Labour MP for Kingswood, said: "The proposed increase in housing development is absolutely unacceptable. There's not a shred of evidence those numbers are sustainable.

"There should be no building on green belt at all."

Politicians also raised concerns about the lack of infrastructure in the region to cope with an influx of new residents, particularly when it comes to transport.

They pointed out how the M4 and M5 are already blocked at rush hour and the strategy does nothing to set out how roads or the public transport system would be improved.

Weston-super-Mare MP John Penrose said the global economic crisis meant the figures used to draw up housing predictions for the next two decades are now useless.

"We all understand that these growth rates are unrealistic, so central premises on which the strategy is based have to be wrong," he said.

Mr Wright insisted that the Government was committed to keeping greenfield areas, but did little to quell the concerns raised.

He said: "Due to the quasi-judicial role of the Secretary of State in this matter I am very, very limited in what I can say.

"The Government is committed to ensuring everyone has access to a decent home in a place they can afford, in a place where they want to live.

"The South West is the only region with above-average house prices and below-average incomes."