A radical organisational shake-up at Birmingham City Council’s schools and children’s social services department will see 84 managers lose their jobs.

Almost 130 senior officials face the prospect of having to apply for only 43 posts in a new slimmed-down structure.

The redundancies are part of a strategy to improve performance at the department, where services for children at risk of physical and sexual abuse were found to be failing by Ofsted and placed under special Government improvement measures.

In addition, the council is to close all 13 Birmingham community day nurseries with 48 job losses for nursery nurses and assistants.

The decision represents a U-turn after council leaders insisted six months ago after a period of public consultation that the nurseries, which cater for vulnerable children, would be saved.

When all of the changes affecting the Children, Young People and Families Directorate have been implemented the council expects to save £21.5 million this year rising to £69 million by 2014/15.

Senior management staff whose jobs are at risk are on salary levels of between £50,000 and £70,000.

They have been invited to attend special assessment days at the University of Birmingham, where they will be considered for roles in the new structure.

A consultation document issued to staff says the council has to make sure “the right person is in the right role” in order to improve standards.

It says a “robust” selection process will be followed, and the assessment days will be externally managed.

The selection criteria for redundancy is based on a 60/40 split between past performance records and expected future performance.

The new structure was approved by the council cabinet in March.

Members were warned about redundancies, but no estimates for the number of jobs likely to disappear were given.

The community nurseries will close permanently at the end of August.

But the council insists that the closures should not be seen as a cut because services currently provided by the nurseries will be merged with children’s centres or family support teams in a bid to save cash. Private nursery care and child minders will also be offered to parents.

Councillor Jon Hunt (Lib Dem Perry Barr), chairman of the education scrutiny committee, said: “If the service is still being provided it is not a cut. Under the new set up more children will be looked after in children’s centres where they will get more holistic support along with their families.

“The key will be making sure that the new places do meet the children’s needs.”

Trade unions are balloting nursery staff for strike action over the job losses which they claim could lead to poorer quality care children at risk.

According to the latest plan 178.5 full time equivalent nursery nurses will be cut to 133 and those jobs transferred to the new integrated family support units or existing children’s centres.

However, three new senior management posts, each worth approximately £50,000 a year, are being increased to oversee the new set up.

GMB union general secretary Roger Jenkins said: “Community day nurseries provide an important service for the people of Birmingham. Most of the children are sent for day care by social services, they are vulnerable children and get a very high degree of attention.

“If these children do not get the right start in life we are storing up problems for future.”

The council was unable to say how many children are being moved to private provision or comment on the management changes.

A spokeswoman said: “As previously stated there are no plans to close the community day nursery service. The nurseries will become an integral part of the children’s centres and integrated family support teams, providing support tailored to each family’s needs, with more equitable provision across the city.

“There has been formal consultation with staff in all service areas where there are proposed changes to service delivery regarding the realigned services, with trade unions and with partners and this consultation is ongoing.”

She pointed out that senior management jobs are being cut back elsewhere in the department.