The three main local government unions failed to persuade employers to increase the London Weighting allowance for their members at a meeting on Thursday.

Refuse collectors, teaching assistants, social workers and street cleaners will be among those workers expected to strike across the capital on 1 October.

The strike will coincide with a speech by Prime Minister Tony Blair to the Labour Party conference.

The fact that there has been no offer is a kick in the teeth for the tens of thousands of low paid workers who are the lifeblood of public services in London

Geoff Martin, Unison

Geoff Martin, London convenor of Unison, said it would be followed by more industrial action aimed at hitting the collection of council revenues.

He said: "The fact that there has been no offer is a kick in the teeth for the tens of thousands of low paid workers who are the lifeblood of public services in London."

Unison, the T&G and the GMB unions represent 100,000 council workers.

They want a flat rate rise of �4,000 a year to help their members meet the costs of living in the capital.

Currently council workers can expect London Weighting allowances of between �1,400 and �2,600.

The unions say this does not bridge the gap between salaries and the high cost of living in the city.

Unison members have already taken part in four days of strike action over what they see as inadequate London weighting.

Disappointed

But the Association of London Government (ALG) said it was disappointed by the plans for another strike.

It said it could not afford the rise in London Weighting after reaching an agreement on national pay.

Ann John, for the ALG, said: "The strikes in May, June and July did not find the missing millions needed to meet the unions London Weighting demand."

She added: "Councils simply don't have the �250m needed to meet their demand.

"Funding the claim would mean a �90 council tax rise or 11,000 job loses."