The true impact of the pay and grading review at Birmingham City Council became clear last night after it emerged that six employees will each have their wages slashed by between £25,000 and £35,000 a year.

The six, who are not being named but work in the transportation and education departments, are the unluckiest losers from the Single Status initiative which is supposed to iron out pay inequalities between men and women and blue and white collar jobs.

In total, 81 council workers will have their pay docked by more than £16,000 a year. A further 4,456 employees can expect their wage packet to shrink by between £1,000 and £10,000.

Almost 19,000 council staff are in line for a pay rise, but only 42 stand to get £8,000 or more. The losers will get a three-year breathing space, when their pay will be frozen.

Deputy council leader Paul Tilsley yesterday described the three-year protection period as "fair and generous".

The council was "bending over backwards" to be as helpful as possible to staff hit by the new grading structure, Coun Tilsley (Lib Dem Sheldon) added. But his remarks were condemned by Labour councillors who pointed out that the majority of losers under the changes were women and the majority of gainers men.

The marathon exercise in re-drawing salary scales for 40,000 people was undertaken by the council's ruling Conservative-Liberal Democrat coalition as part of a Government initiative to make local authority pay fairer.

The cost to council taxpayers of implementing the new system will be £29 million a year by 2011.

Furious unions at the Council House are balloting their members for industrial action, while more than 16,000 staff have refused to accept their new employment contracts.

A breakdown of winners and losers from the new system was released by cabinet equalities and human resources member Alan Rudge following pressure from Labour councillors.

Sir Albert Bore, leader of the opposition Labour group, said he could "scarcely believe" what was being proposed.

Sir Albert listed several "unfair" examples: n a single mother will have her pay reduced by £12,000, almost halving her salary n a member of staff, already low-paid, will have his salary cut from £17,000 to £13,500 n a couple both working for the council - one will lose £3,500 a year and his partner £2,500 Coun Rudge (Con Sutton Vesey) insisted the overall impact of the new structure would be fairer.

More than 30 separate pay grades are to be replaced by seven new grades. He rejected Labour demands to increase the number of grades, which would reduce the number of employees suffering wage cuts.

Coun Rudge said the use of more grades would "fail to close equality gaps, fail to promote flexibility and performance, fail to remove overlaps" and would be £12 million a year more expensive to implement.

He said 46 per cent of staff had now accepted their new contracts, a figure that was "increasing all the time".

Coun Rudge is also planning to scrap bonus payments to thousands of blue collar workers, including street cleaners and binmen. The payments, in some cases more than £10,000 a year, which are made regardless of performance, are illegal, according to Coun Rudge.