More than 300 Sutton Council workers are on controversial 'zero-hour contracts'.
But the council has defended its use of the contracts, which allow work and pay to be stopped without notice, by saying they are a "necessary evil".
Zero-hour contracts are used to create on-call working patterns where employees are not paid a salary, they are paid only for the hours they work.
They are regularly used to employ students or retired people who want to do work when it suits them.
But they have attracted criticism as they may be exploited by unscrupulous employers to deny employees work for any reason.
Business Secretary Vince Cable has said they need closer regulation but ruled out banning them.
Last week it was revealed that Sutton Council employs 334 people on zero-hour contracts after a question was raised by Labour Councillor John Keys, who said he had been employed on one such contract and described it as "no fun".
Liberal Democrat Coun Colin Hall replied: "We have 334 current members of staff on zero-hour contracts in things like arts and leisure and supply teachers.
"When engage staff in zero-hour contracts it's when people are on holiday or off sick or where there is a seasonal demand for work."
Conservative Coun Tim Crowley asked Coun Hall to explain why the council raised concerns about McDonald's' use of zero-hours contracts at a recent meeting relating to a new restaurant opening in Wallington when the council itself uses them
Coun Hall said: "There are zero-hour contracts and there are zero-hour contracts. There are contracts where you must only work for one employer and there are those that allow you to work for others - like ours.
"Sometimes zero-hour contracts are a necessary evil and sometimes they are really unpleasant."