More than 50 staff went on strike in Newtown

In the first phase of a drive to scale down the civil service, 37 jobs centres and benefits offices across Britain are to close - seven of them in Wales.

Union officials are warning that up to 800 Welsh jobs could go.

Other wildcat strikes, involving hundreds of staff, have taken place in Fife, Scotland and in Manchester.

As part of the cuts, at least 70 people working in Newtown will either lose their jobs or be asked to transfer, although the office will not be shut.

Workers say they feel badly let down after coping with a major reorganisation of the service in the past few years.

Mark Milne, the Public and Commercial Services (PCS) union representative in Newtown, said the job centre had met all its targets and claimants would suffer with a much poorer service.

Under the plans, the Welsh offices facing closure are Rhyl, Wrexham, Aberystwyth, Carmarthen, Neath, Cardiff and Barry.

Their work will be taken over by so-called super-offices in Llanelli, Swansea, Merthyr Tydfil, Caerphilly and Newport.

The changes should be completed by March 2006.

'Decimation'

Head of the PCS union Mark Serwotka has said the wave of job losses were "the first phase in the decimation of services to the vulnerable".

He said the closures would see offices shut down in "some of the poorest communities in Britain hitting the long-term unemployed and some of the most vulnerable in society".

Earlier this week, Mr Serwotka announced his members would be balloted for a one day strike on 5 November.

The Department for Work and Pensions has said it will try to avoid compulsory redundancies and will attempt to relocate staff.

Alan Johnson, the Work and Pensions secretary, said the closures were part of a modernisation programme aimed to make services more efficient.