Forty angry red zone property owners are launching a legal battle to force Gerry Brownlee to change his mind over compensation.
They have engaged high profile lawyer Grant Cameron to file proceedings in the High Court next week for a judicial review.
Mr Cameron said his clients were owners of vacant land and uninsured properties in the red zone, and called themselves "quake outcasts".
"The issue is whether or not they should accept the Government's offer of 50 per cent of the value of their land," Mr Cameron said.
The claimants want the same compensation offer other red zone properties owners received - the 2007 rateable value of their properties.
Bare land cannot be insured, which left many people facing huge financial burdens when the February 22 quake struck.
In an interview this morning, Mr Brownlee stood by the Government's red zoning of properties in spite of the protests.
The Earthquake Recovery Minister told Radio New Zealand the challenge was "wishful thinking" and the zoning was appropriate.
"What we're saying is the land has changed in its nature ... . It's not a matter of just magically changing the geology of the area by lifting a designation. The designation is trying to acknowledge the changed geology of the area," he said.
More than 200 red zone property owners have refused the Government's voluntary buyout offer, which expired on Tuesday.
The Canterbury Earthquake Recovery Authority has warned of several risks for those who refused the offer.
The area had "considerable challenges" for rebuilding and maintaining basic services such as water and sewerage, Mr Brownlee said.
"It's not reasonable that the rate-paying base for the rest of Christchurch pays undue amounts to maintain services into areas where its known the ground is such that residential occupation is undesirable," he told RNZ.
"It's inevitable that they are going to live with a lot less reliable sources of sewerage, water and waste water disposal."
The ground would move and further damage was likely, insurers might not renew policies, and banks might not be willing to lend in those areas, said Mr Brownlee.
Mr Cameron said there was "no logical reason" for the Crown to the approach it had, nor to differentiate between insured and uninsured owners.
"The Government has said regularly that it would help those disadvantaged in the Canterbury earthquakes and offered to purchase properties from affected people.
"If they are genuine in their social conscience and want to help people, then they should treat them in the same way," Mr Cameron said.
The current offer was "minimising the liability for the taxpayer," but disadvantaging those worst affected by the earthquakes.
Mr Cameron said the High Court had created a fast-track option for legal action related to the earthquakes and the judicial review would take advantage of that.
He hoped for a "very early hearing", but said regardless of the outcome the findings might need to go to the Court of Appeal and that would not be before next year.
Wellington-based Queen's Counsel Francis Cooke was preparing legal papers and making some adjustments before filing the documents.
Mr Cameron said he was "very confident" of success.
"It's going to make for a very interesting and dramatic court case," he said. "Obviously we think the Government's position is untenable."
- Star Canterbury with APNZ