The campaigners against the pounds 200m, four-mile M11 link road in Wanstead, east London, took over a row of four shops last week, but demolition contractors working for the Department of Transport, which owns the houses, smashed their way in.
In an early morning battle with the squatters, two of the houses were bulldozed but the protesters managed to retain control of two.
Last month, 1,000 police and bailiffs evicted 300 protesters from the self-proclaimed republic of Wanstonia, three houses in Cambridge Park, and in December there was a confrontation over a tree on George Green opposite the tube station.
Yesterday, at an 'open day' for the new squat, Neil Cornish, one of the occupiers, said: 'They were demolishing the top floor of the houses while there were people on the ground floor with rubble falling on them. They could have killed someone.'
The police eventually arrived and put a stop to the demolition and the Department of Transport is seeking a court order tomorrow to evict them.
A dozen protesters spent last weekend repairing the damage to the houses and set up an information centre in one of them. They are angry that the four houses are shown at the link road information, run by the civil engineers, W S Atkins, as being still standing in an artists' impression of how Wanstead will look after the road is built.
James Creed, who was manning the office yesterday, was unapologetic: 'I can't accept it is misleading. It's only four shops. When the picture was done, that was how it was expected to look like. I don't know why they are now being demolished. You will have to ask the Department of Transport.'
A spokeswoman for the department said: 'At first it was thought we would not need to demolish them, but now they're needed for statutory undertakers, gas and electricity. There's nowhere else for them.'
The protesters are unperturbed by the prospect of another eviction struggle. John Bex, a veteran campaigner, said: 'We're making them fight every inch of the way. Each delay means their bill gets a bit higher.'