A controversial pay and grading review at Birmingham City Council, which will leave 5,000 employees worse off, has been delayed.

The council cabinet is to reconsider the Single Status salary shake-up, under which bonuses worth up to £10,000 a year will be axed.

The new system, covering 40,000 local authority workers, was to have been introduced on Monday. But the main scrutiny committee is using its powers to insist that the cabinet think again.

Committee chairman Alistair Dow said there were two matters of particular concern. He wanted further consideration to be given to the implications of removing the current bonus arrangements, and there was also a question over whether a consistent approach had been adopted in communicating and consulting with staff on the job evaluation process.

There are concerns the council will be leaving itself open to legal action if employees can show they have been treated unfairly. The main council union Unison is balloting its members for a possible strike. Coun Dow (Lib Dem Selly Oak) said he feared employees who were members of trade unions had "more said on their behalf" than staff who were not represented by unions.

Coun Dow added: "I would say we are trying to help the cabinet be as confident as they can be that they are getting this right so that most people will feel happy about the outcome. We are applying a gentle hand on the tiller.

"You will never get everyone happy in these circumstances because there will be some losers. But we want to make sure this process is handled as fairly as possible."

Under the new pay system, designed to eliminate wage inequalities between men and women and blue and white collar staff, 42 per cent of council employees will be better off, 46 per cent will continue to receive their existing salary, and 12 per cent will suffer a pay cut.

Scrutiny committee member Ian Ward, deputy leader of the opposition Labour group, said: "Bonus earners are at risk of losing substantial amounts of money. We want to be absolutely certain that the process of consulting and evaluating people's jobs has been conducted scrupulously and fairly."