If the employers fail to respond, the unions will look at a further day of all out strike action across London on a date to be fixed. It will be used to launch a program of selective strike action designed to achieve maximum disruption of council services with minimum impact on the elderly and vulnerable.
The unions will meet in early September to finalise their selective strike action plans. Unison members in London have already taken part in four days of strike action over the London Weighting claim.
The three unions represent over 100,000 workers in 32 London Boroughs.
They believe the employers have no option but to come to the negotiating table with a realistic and positive offer.
Roger Count, senior officer in GMB said: 'My members are prepared to continue to take action in support of the claim. We had an 83% response in support of taking strike action in our recent ballot.'
Peter Denman, of TGWU said there were groups of his members who would take action on a selective basis which would damage the ability of London boroughs to provide quality services to the public.