It comes after a new report shows the council is still issuing more summonses than any other London borough, with the second highest use of bailiffs in the capital.
CTS provides financial assistance to Council Tax payers on low incomes.
The Green Party says Lambeth council should stop using bailiffs in cases where residents in receipt of CTS fall into debt, following the example set by Bexley, Brent, Islington and Southwark.
In January, Lambeth council promised to review its policy.
However, the report “Too Poor to Pay”, published by the Child Poverty Action Group and charity Zacchaeus 2000 last week, says has been no significant change.
Green councillor Scott Ainslie said: “The way Lambeth’s cuts to Council Tax Support are being implemented is putting an unbearable burden on those who can least afford it.
“Labour can no longer claim ignorance on this issue or blame central Government. They know the terrible impact that their policies are having, and they know that other boroughs are pursuing different policies which are protecting the poorest residents.
“Lambeth is more punitive than any other London borough.
“The approach is also self-defeating. When low-income residents are already trying to find the money to pay for the council’s cuts to their support, the summonses and unnecessary court charges are pushing residents further into hardship, and making collection even more unlikely.
“The receipt of a court summons is an intimidating experience that can have a severe impact on the physical and mental well-being of someone in a vulnerable situation. Lambeth Council should reverse its cuts to Council Tax Support. It should minimise court costs as other boroughs have done and refrain from using bailiffs in Council Tax Support cases.”
However, Cllr Paul McGlone, Lambeth’s deputy leader, said the number of cases referred to bailiffs had been reduced and that the council had introduced a new support scheme for residents.
He said: “Firstly last financial year we cut the number of cases referred to bailiffs by half. Further for 2015-16 no cases have been passed to the bailiff which is purely as a result of the interventions put in place to deal with debtors individually.
“But the background to this is also important – we have to be financially responsibly and make sure that money owed to us is collected as the delivery of more than 100 key services depends on it.
“A large number of people initially fell into debt after the Government passed responsibility for the Council Tax Support Scheme to councils – but with a 10 per cent budget cut leaving both the council and many vulnerable residents at a disadvantage.
“In response to the situation we developed a new support scheme to stop people falling foul of the new funding regime. Sadly the report Too Poor to Pay fails to recognise this, or the ongoing work in Lambeth that is being carried out to help our vulnerable people who are in debt.”