Human Resources bosses at Birmingham City Council insisted last night they could do nothing to improve the lot of 24,000 local authority workers who will be paid no more than £333 a week when single status employment reforms come into effect.

They blamed the low wages on market forces which could not be resisted.

Alan Rudge, the Tory cabinet member responsible for equalities and human resources, said inequality between a small number of very highly paid officials and the low salaries for the vast majority of staff was a "fact of life" in the public sector and in private industry.

Abolishing the lowest pay grade, where 6,000 council employees receive as little as £215 a week, would cost £5.6 million and result in a 45 per cent pay rise for many of those affected, Coun Rudge said.

However, he warned such a move would be illegal because the council is prohibited from paying wages excessively above market rates.

There could be "no possible justification in law" for doing so, he insisted.

Andy Albon, the council's director of human resources, who has masterminded the single status initiative, said local authorities historically employed a large percentage of their work-force in low-paid jobs.

This was an economic fact that could not be denied, he added.

The pair were responding to The Birmingham Post's disclosure yesterday that single status will leave 35,000 council workers earning less than £23,176 a year - £445 a week.

The national median wage for men and women in the UK is £451 a week.

However, 24,000 city employees, will earn less than £17,400, or £333 a week. They include school cooks, home care assistants, teaching assistants and caretakers.

The council insists that a fairer comparison would be the average wage for Birmingham, which is £412.

Coun Rudge (Con Sutton Vesey) insisted that single status, a Government directive to introduce equal pay for equal work and iron out gender discrimination in wage rates, would improve salaries for 16,000 low-paid workers. More than 1,000 employees will see their wages rise above the £17,400 mark.

Many female employees have also received hefty back pay awards reflecting years of being treated unfairly compared with male workers, in some cases totalling £20,000.

But 4,400 members of staff have been deemed to be earning too much for the job they are doing and will suffer a wage cut following the single status grading review, which comes into effect at the end of September.

Coun Rudge said the changes, taken as a whole, would result in far more winners than losers and should be welcomed.

"This is a very good deal for our workforce. Without any doubt, single status results in lower paid workers being considerably better off than they have been. It is a good move forward," Coun Rudge insisted.

He hit out at Labour, which has criticised the single status changes, claiming the party had "disgracefully failed" to deal with wage inequality during its 20-year stewardship of the city council.

Coun Rudge added: "We have been able to deal with genuine inequalities and eradicate them. For years Labour failed dismally to face up to the problem and left us to deal with it in a very short period of time."

He disclosed that the council's highest paid staff, the chief officers and departmental directors, who are outside of the single status process, will be subject to a separate grading review.