The council has come under fire for investing millions in tobacco companies despite now being responsible for helping Sutton smokers quit.
Councils became responsible for promoting public health - including encouraging people to quit smoking - on Monday as part of Government reforms to the health service.
Yet Sutton Council invests money from its pension fund in tobacco companies. Campaigners have said the position is hypocritical and has called on the council to follow other authorities' examples and change its investment strategy - something the Sutton Council says it cannot do.
It says it has a legal responsibility to get best value out of taxpayers money it invests.
Councillor Graham Whitham, leader of Sutton's Conservative opposition, said: "Having seen the anti-smoking campaigns at a local and national level it is reprehensible that the council is being so hypocritical.
"Often with this council it's 'do as we say, not as we do'.
"Councils have a duty to get the best value out of their investments. But there comes a time when, even if the financial case stacks up, there is a question of responsibility.
"Just because tobacco companies are making huge amounts of money by poisoning people, it doesn't mean we have to encourage them - there must be other good investments out there."
Action on Smoking and Health (ASH) research manager Amanda Sandford added: "Sutton Council should join the growing band of other local authorities that have pledged to disinvest in tobacco and to place their pension funds in more ethical businesses."
Sutton Council has confirmed it has money invested with tobacco companies but says it is unable to establish exactly how munch as its funds are managed by experts and split across a wide range of investments.
Councillor Roger Thistle, chairman of Sutton Council’s pension committee, said: "Councils are obliged to obtain best value from lawful investments, therefore decisions have to be made purely on a basis of maximising financial return.
"The London Borough of Sutton’s pension fund investments are in pooled vehicles which may include investments in tobacco companies."
Councils in Essex, Staffordshire and Norlfolk say they are reviewing their investment strategies now they have a responsibility for public health.