Up to 400 jobs will be axed from Birmingham City Council’s adults social services department as the local authority steps up its cost-cutting drive.

Cabinet member Sue Anderson said most posts would disappear from administrative and managerial positions, reflecting a shift to a “leaner, meaner workforce” better suited to providing front-line services more efficiently.

The figure is on top of 800 redundancies across the local authority announced last month by council leader Mike Whitby.

The cull from social services represents almost ten per cent of the adults and communities department workforce. Coun Anderson hoped staff could be retrained and remain with the council. But compulsory redundancies could not be ruled out.

The opposition Labour group described the move as a “kick in the teeth” for workers before Christmas.

Formal consultation has begun with 300 managers and all staff have been invited to volunteer for redundancy.

Coun Anderson (Lib Dem Sheldon) said several factors were behind the decision including the introduction of personal budgets which allow elderly people to shop around and choose services from private sector providers rather than the council.

The planned closure of 29 council-run old people’s homes, with 16 already shut, seems certain to mean redundancies.

In addition, a business transformation programme enabling social care assessments to be carried out electronically is squeezing out clerical jobs while anticipated public spending cuts in 2010 means that the council is looking to make substantial savings.

Coun Anderson said that the decision to trim the workforce was not entirely driven by a desire to cut costs. She said: “We are looking to reorganise the structure in terms of how many staff we need for an efficient department. We are looking for a more efficient workforce, at what we need for a well-run adult social care department, while making sure we can protect front-line services.

“We are looking to a leaner, meaner workforce, but we don’t want to get rid of people who have really good skills.”

Deputy Labour group leader Ian Ward said mounting job losses at the council called into question a pledge two years ago by city chief executive Stephen Hughes that “no one will be sacked” from posts lost through business transformation. Coun Ward (Lab Shard End) said: “Those words sound very hollow now. People are being made redundant and the length of time the council allows to find alternative employment before dismissing staff has been reduced to three months.”

He said the so-called Employee Bargain devised by the council’s controlling Conservative-Liberal Democrat coalition, which promised to safeguard employment in return for a more flexible attitude by workers, was “not worth the paper it is written on”.