Help the council to decide which services should be kept, reduced or cut.
The authority wants to know how you think services could be delivered differently and what the council's priorities should be.
Although the outcome of the Government's spending review was announced last month the full implications for Southwark will not be known until December.
"There remain many unanswered questions about exactly how funding will be allocated," says Cllr Peter John, leader of the council.
"But one thing is for sure, these funding reductions will impact on services.
"The public sector will change beyond recognition and we will be judged on how we manage that change."
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