Prison officers have called for urgent meetings with ministers after Justice Secretary Jack Straw said he was "actively considering" banning strikes.
Prison officers say the threatened ban contravenes their human rights
The leader of the Prison Officers Association, Colin Moses, said the plan would "criminalise" his members.
Mr Straw's comments, made in the Commons on Tuesday, follow the first national 24-hour strike by prison officers in August.
The government has accused the POA of reneging on a voluntary strike ban.
Although the union gave notice in May this year that it no longer wished to be bound by the agreement - reached in 2005 - Mr Straw said the union had not given the agreed 12 months' warning before taking industrial action.
On Wednesday the Ministry of Justice said it was seeking a new TUC-sponsored agreement with the prison officers.
But it added: "We will have to consider carefully whether to reapply statutory provisions against strike action if talks fail."
Mr Moses said: "This is a disgraceful act by a Labour government who promised to remove anti-trade union legislation whilst in opposition. Yet now they are looking to re-introduce legislation that will criminalise POA members for trying to exercise their human rights as workers."
Jack Straw says prisons need protection from disruption
The union says it intends to defend its right to strike with "whatever action necessary".
"We will not allow a Labour government to use the courts to resolve its problems," said Mr Moses.
The POA strike in August followed a government decision to spread the officers' independently assessed pay award over two stages rather than one.
The union says this effectively means a rise of 1.9%, rather than the 2.5% recommended by the Prison Service Pay Review Body.
The Ministry of Justice says the strike in August had "an immense impact" on the operation of the prison service, leading to cancelled court appearances and prisoner transfers, and disturbances at a young offenders institute.