City Hall union leaders today claimed a key victory against the Government after their withdrawal of tomorrow's threatened Council strike action.

A potentially crippling 24-hour walk-out involving around half the authority's 20,000 staff was called off following Government-level talks over changes to workers' pensions.

Unions were furious over plans to raise the pension age for local government workers from 60 to 65, due to come into force on April 1.

Ministers have now agreed to revoke the changes, preventing action by a million council workers nationwide.

Unison's Bradford branch spokesman Patrick Kerry said: "Our objectives over the few months had been to get the Government to open negotiations on pensions and to get the April 2005 order lifted.

"We have achieved both of those objectives and we now look forward to entering into real negotiations about the future of the pension schemes."

He said negotiations will now take place at a national level adding: "The trade unions have sent a warning shot to the Government not to mess with workers' pensions or they will have to face the consequences."

Unison general secretary Dave Prentis, who led the recent talks, said: "I am pleased that the Government has listened. Our aim throughout talks with the Deputy Prime Minister has been to have these regulations revoked and to have real negotiations on how we can have a viable, sustainable pension scheme that will benefit all."

The Government had always argued that reform was needed because people are living longer, but admitted to "misunderstandings and suspicion" of its plans.

The strike was to be staged by members of Amicus, T&G, Ucatt and Unison - Unison alone has 9,000 members working in virtually all areas of Bradford Council.

A Bradford Council spokesman welcomed the announcement and said all its customers can expect its services to be unaffected tomorrow.

He said: "We are pleased the strike will not now be taking place tomorrow and that all services will be delivered as normal."

Deputy Prime Minister John Prescott is now expected to set up negotiations between the Government, unions and employers, to discuss the future of pension schemes.

Mr Prescott said: "Following constructive dialogue on the local government pension scheme, I have decided, with the agreement of all parties concerned, to establish a tripartite committee, which I will chair.

"The key stakeholders will consider and negotiate the long-term future of the scheme."