How is it legal to throw someone out of a home they rightfully own?

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In a road near where I live, all but 3 of the houses are derelict. The council have decided to pull it all down as it's a blight on the area. However, people live there. The situation for these people - one couple have lived there, in their own house, for 40 years - is to accept the amount that the council will pay (market value - as in, not much, as the street is all boarded up) or try to fight a made decision and get kicked out by bailiffs in a few months. How can this be? How can we help them fight their corner?