Senior managers at Bradford Council were in crisis talks with union bosses today to find out which services will be hit by a strike a week from today.

Around half the authority's 20,000 staff could walk out next Wednesday - potentially crippling much of its work.

Members of four unions - Amicus, T&G, Ucatt and Unison - have voted overwhelmingly in favour of the one-day strike against proposed changes to pensions.

City Hall chiefs have been trying to find out how many staff are likely to take part so they can plan for the action.

Unison alone has 9,000 members in the authority and its officials expect their full support. A spokesman said it has members in virtually all areas of Council operations.

Apart from street cleaning and bin collections, Unison says a walk-out by its staff could also close City Hall, the district's town halls, Britannia House and the bdirect "one-stop shop" in Forster Square.

Negotiating lists were also being drawn up today outlining areas of service which may be exempt from industrial action.

Unison spokesman Patrick Kerry said the young and elderly would be protected and not left without Council care.

He said: "Feelings among members who regard themselves as the 'poor relations' of the public sector are running high and we expect full support from our members.

"They have paid their pension contributions week in, week out, are very angry and are not prepared to sit back and accept changes by a Government which promotes choice except when it comes to local government workers."

A Bradford Council spokesman remained hopeful offices would open, saying thousands of staff are not members of any union and many others don't have a local authority pension.

He added: "This is a national issue and employers are negotiating nationally with unions to agree which services will be exempt from action.

"We are also negotiating with the local union branches. We are making contingency plans and once the union negotiations are complete we will be in a better position to identify the likely effects on services to the public."

The GMB union says it will not be taking part in the industrial action since it is still talking with employers and the Government. Its 1,300 members employed at Bradford Council include street cleaners, bin men and school kitchen staff.

Terry Patten, the GMB's branch secretary for Bradford, said: "Our position is that we have not had a vote, so our members should be working as normal. If they don't then they are breaking a national agreement."

Mr Patten said he expects no problems if his members cross other unions' picket lines: "Hopefully, common sense will prevail, but we take our own decisions, we don't follow suit."

But Unison's Patrick Kerry warned that if picket lines are crossed his union may no longer take GMB views into account when taking part in joint negotiations with employers.