Church services, tea parties and even a medically themed symphony are on the agenda as Britain marks the 70th anniversary of the National Health Service—a battered but beloved institution facing an uncertain future.

Public buildings were being flooded in medical blue Thursday and prayers were being said at Westminster Abbey to celebrate the state-funded service, launched on July 5, 1948, in a country shattered by war.

The NHS principle of free medical treatment, funded by taxation, retains wide support. But it has been challenged by rising , increasing patient expectations and the vagaries of government funding.

After a spike in ambulance delays and canceled operations this winter, Prime Minister Theresa May last month announced the service would receive 20.5 billion pounds ($27 billion) in extra funding by 2023-24.