The first day of strike action will take place on Tuesday 14 May unless the employers return to the negotiating table.
'Unison's local government members in London have spoken out against low pay in the capital. If councils are serious about delivering world class public services in London they must pay decent wages to their staff.
'A growing number of public service workers are being forced to leave London because it is so expensive - how much further do essential services have to decline before the government is prepared to do something about it?
'It is ridiculous that investment in our public services should somehow be divorced from investment in the very people who deliver them.'
Unison's chair of local government in London, Dave Eggmore said:
'All our members in London local government are asking for is to be treated fairly and paid a decent salary, so they can afford a decent living. London is the most expensive capital city in Europe and vital public service workers are leaving, resulting in many jobs going unfilled and services on the brink of collapse.
'With the police now paying up to£6,000 in London allowances and many inner London nurses getting over£4,000, it is about time local government workers caught up. Our members' claim of£4,000 is not excessive and a flat rate would help the poorly paid the most.
'From classroom assistants to social workers, from school meals workers to home helps, Unison's London members provide the services which are the very fabric of a decent society. It is high time they were rewarded and poverty pay was removed from local government in London.'
NOTE ON LONDON ALLOWANCES FOR OTHER PUBLIC SECTOR WORKERS:
AUDIT COMMISSION STAFF
Audit Commission staff get£4,492 plus a travelcard from their home station.
NURSES and MIDWIVES
A qualified G grade nurse at the bottom of her range could receive£1,750 on top of an inner London Allowance of£2,365, a total of£4,115 extra for working in London. From 1 April 2001, the London Allowance was increased by 3.7% to£2,365 (inner London) and£1,684 in outer London.
Staff in London also receive 5% of salary up to a maximum of£750 in inner London and 5% up to maximum of£750 in outer London, as well as cost of living supplements for qualified nurses of 4% of basic salary, excluding London weighting, with a minimum payment of£600 and a maximum of£1000.
Police officers appointed on or after 1 September 1994 and not receiving housing allowance have a London Allowance of£4,338. Officers in service before 1994 and receiving housing allowance of approx£5,000 get London Allowance of£1,011. Police Officers also receive free travel to work by public transport.
London weighting for teachers rose by 30% last month to£3,105 on top of a basic salary increase of 3.7% for teachers in England and Wales.