The government could withdraw its new offer over public sector pension reform and consider tougher strike laws if trade unions go ahead with a mass public sector walkout this month, a minister involved in the talks said on Sunday.

As many as two million workers could strike on November 30 in what would be Britain's biggest industrial action for a generation after members of more than 20 public service unions backed the move over the overhaul of the pension system.

At the start of the month, the government offered a revised deal to help resolve the dispute but Cabinet Office Minister Francis Maude said this could be taken off the negotiating table if unions pushed ahead with a wave of damaging strikes.

That is absolutely within our power to do that. We have made it clear this is not an unconditional offer, he told BBC TV. We will have the ability to withdraw it and impose something. We said this is as good as it gets.

The government wants public sector workers to contribute more, retire later and receive pensions based on average earnings rather than their final salary.

It argues the changes are needed because people are living longer, represent a far better deal than those in the private sector could obtain and will actually benefit the lowest paid.

Its revised proposal would allow workers to build up their pensions quicker while those within 10 years of retirement would see no change.

However, unions have pushed ahead with plans for a strike, although many ballots have seen low turnouts, and Maude said they had jumped the gun as discussions were ongoing and a deal was very close in some sectors.

He warned ministers might consider laws to ban strikes which did not have significant backing from union members.

I have made this point to the union leaders that if they do call out their members on strike at a time of huge fragility for our economy ... then the case for reform of the ballot laws will become very pressing, he said.

Some union leaders have warned of months of industrial unrest, but Maude said he did not expect this.

I don't sense to be honest any appetite amongst most of the union leaders to go in for protracted prolonged industrial action, he said.

(Reporting by Michael Holden; Editing by Elaine Hardcastle)