Some of Norway’s leading lawyers, including the celebrated defender of the mass killer Anders Breivik, have come forward to condemn proposals for a new coronavirus law giving the government enormous emergency powers.

The law, which was proposed at a special council chaired by King Harald V on Wednesday night, will allow the government to override all existing laws apart from the Norwegian constitution and human rights legislation until it expires in December.

Geir Lippestad, who won admiration for the way he represented the far-right killer, described the new crisis law as “madness”.

“Setting aside democracy and legal due process for all us in order to govern?” he protested in an interview with the broadcaster TV2. “The right medicine in times of crisis like this is not to weaken the legal security of us all, but to manage and communicate directly and clearly.”

Morten Walløe Tvedt, senior researcher at the Fridtjof Nansen Institute, said that the law could open the way to an authoritarian state.

“The law gives wide powers to do anything,” he said. “If, for example, the government decides to intern everyone infected without providing any medical assistance, and just lock their doors, they have the authority to do so. I’m not saying the government will do this, but in principle they can.”

Hans Petter Graver, law professor at the University of Oslo, also complained in an interview with state broadcaster NRK, that there was no limit to what a future government would be able to do with the law.

Terje Einarsen, a law professor at the University of Bergen, told the Dagbladet newspaper, said that bringing into force such a law without public debate was “very undemocratic”.

He condemned the country’s Labour party opposition for negotiating and agreeing behind closed doors.

“It is unheard of that the the opposition has continued with this for several days and accepted this without any form of public debate,” he said. “MPs will be abdicating when this authorisation is accepted tomorrow.”