A petition against the planned closure of Lewisham A&E and maternity units has been handed in to Downing Street.
The closure would be part of a reorganisation aimed at rescuing the South London Healthcare Trust - which has been put into administration.
The petition was signed by 22,500 people, including consultants and GPs.
The proposals have been made by the Trust Special Administrator (TSA) which said they would ensure health services are sustainable in the long term.
The proposals for Lewisham are part of a bigger plan to restructure the hospitals in south-east London.
Last month, a march was held to protest against the plans. Campaigners said more than 12,000 people had attended.
The TSA's public consultation on its proposals runs until 13 December.