Members of the Public and Commercial Services Union said that they were seriously concerned that the drive to increase the number of volunteers used by the Met could lead to job cuts among paid staff.
The petition says the staff "demand that the Metropolitan Police Service employs real staff on a proper wage, instead of devaluing police staff by using the cheapest option available to police London".
Unison, which represents civilian police staff outside London, has already passed a motion in favour of "lawful non-co-operation" with volunteers.
The development comes just a week after Dame Elisabeth Hoodless, executive director of CSV, called on the public services to open their doors to more volunteers (Third Sector, 27 September).
John Thornton, national officer of the PCSU said: "There has yet to be any instruction from a national level. This is something that has been initiated at a local level because staff have real concerns about job cuts."
Volunteers have been used by the police for some time, but Thornton said there had recently been a "huge increase" in numbers and the figure was set to grow even more.
"There's a big difference between a retired volunteer coming in to look after the flowers in some back-of-beyond police station and some of the jobs volunteers are doing now," he said. "We have heard of volunteers doing HR and clerical jobs."
Thornton added: "The Met says volunteers are adding value, but it's sometimes hard to know what the difference between paid staff and volunteers is."
A spokesman for the Metropolitan Police denied there was any problem about the use of volunteers in the force.
Andy Forster, policy and campaigns strategist at Volunteering England, said: "Greater care should have been taken to address the insecurities of paid staff about job cuts."
- Members of the Public and Commercial Services Union are collecting names on a petition calling for non-co-operation with volunteers working for the Metropolitan Police
- The union is concerned the increased use of volunteers could cause job losses
- Unison has passed a motion calling for non-co-operation with volunteers.