THE government's management of benefit payments was branded chaotic last night after it emerged that one million people - one in three claimants - have been unable to get through to a new computerised call system.

Operated by EDS, the US computer giant, the system is used by Jobcentre Plus call centres to allow people to claim over the telephone. In Scotland, the service handles some 670,000 customers.

Between April and September, an average of a third of calls went unanswered. In Sheffield, it was two in three.

Many claimants were said to have spent hours trying to get through and staff sometimes took two weeks to return calls to fill in forms over the phone.

Unions said claimants for benefits like income support and jobseeker's allowance were waiting up to eight weeks for their first payments, with many having no other financial resources to draw on.

Mark Serwotka, general secretary of the Public and Commercial Services Union, called on ministers to halt a round of 30,000 job cuts at the Department forWork and Pensions (DWP). He said claimants were venting their frustration on front-line workers with a 66-per cent rise in assaults on staff since the system launched.

"We think this is an inevitable consequence of Gordon Brown's efficiency drive, " said Mr Serwotka. "He says computers can replace people. This is categorical proof that not only do the computers not work but that when you force vulnerable people to go through call centres to access the benefits system, if there's not enough staff and computers don't work, a million people have tried to get through and can't."

He added: "We believe the system of removing local access to the benefit system is fundamentally flawed. The government has invested millions in this and we doubt that they will go back on it. Our view is that until all this works perfectly, all the staff cuts must stop, " added Mr Serwotka.

A spokesman for the DWP said the situation was improving, with nine in 10 calls getting through last week.

Tim Boswell, Tory work and pensions spokesman, urged ministers to "get to grips"with the system. He said: "With a fourth secretary of state at the Department of Work and Pensions in less than 14months, it is no wonder there is still chaos and confusion. I hope John Hutton sticks to his timetable of reform and delivers the much-needed results."

Davis Laws, Liberal Democrat spokesman on work and pensions, criticised "yet anotherwelfare reform disaster".

Scotland's top civil servant warned yesterday that government bodies must share more of their information technology systems.

John Elvidge, permanent secretary at the Scottish Executive, said examples showed savings of 30-per cent could be made while improving services.