Public sector workers who will stage a 24-hour strike today warned of indefinite industrial action to protect their pensions.

Up to 80,000 local government workers across the Midlands will walk out today in the dispute.

Every place of work manned by local government members of Unison or the other public services unions taking part - including the T ransport and General Workers Union, Amicus and the GMB - will be subject to Christmas Day staffing levels.

A spokesman for Stafford-shire Police said the action meant the public could notice a delay in getting calls answered at public inquiry desks.

Both police stations' "back room" public service desk and the front-of-house help desks are manned by local government staff.

"We imagine that our call-taking functions will be affected to some extent," said the spokesman.

"It may take people longer to get through to speak to someone than normal. We are putting a lot of focus on making sure 999 calls get priority."

Picket lines are expected at the majority of the 240 centres affected in Birmingham, including libraries, leisure centres and benefits offices. Lancaster Circus House, where about 1,000 people work for the city's engineering, property and finance departments, will see one of the biggest, and Birmingham's Central Library will be the site of another.

Between six and seven workers will demonstrate outside Aldridge Road Day Centre, a council-run service for people with learning difficulties. The centre will be closed today because too few staff will be turning in to ensure minimum safety standards for clients.

Georgina Preston, aged 48 ,from South Woodgate, has worked for Birmingham City Council for 32 years and the Aldridge Road Day Centre for 17 years. She will be joining a picket line outside the centre today and said she was prepared to strike as many times as necessary until a clear message went through to Government.

Mrs Preston, who teaches clients gardening skills, said she had been paying into her pension since she started with the council.

"I think it is disgusting that the Government is allowed to get away with attacking our terms and conditions," said the mother-of-one.

"I am sent a pension fore-cast every year and nowhere has it been said that the fore-cast was for paper purposes only.

"If I knew 30 years ago it might change I might have looked into buying an extra pension."

She said a scenario where teachers were able to retire at 60 but teaching assistants had to work until 65 was ridiculous.

"Civil servants' pensions are exempt from the changes and I work just as hard as them so why should I be be treated differently?

"I don't have a lot of disposable income to put aside and a lot of people are less well paid than I am, so God knows how they will manage."

Members who are not at picket lines are expected to attend large rallies being staged outside local government headquarters across the region.

The rally in Birmingham's Victoria Square is expected to be the biggest, with addresses by regional union leaders.

"This action has found overwhelming support by members," said Caroline Johnson, Unison assistant regional secretary for the West Midlands.

"At the end of the day, £3,800 is the average local government pension. It's not a huge amount of money. People like Georgina have been paying into a pension for 32 years and are now being told by Government they won't get what they have been paying for.

"But we are trying to make a point to Government, not to vulnerable people and members responsible for their safety have been given exemption from the action.

"If an agreement is not reached on this matter more industrial action is in the pipeline."