A council spokesman said: “Without these works being carried out there is the risk that the garden could lose its listed status.”
The public currently has 24-hour access to the park.
It’s public toilets have been closed as they have been the focus of anti-social behaviour and vandalism.
The council spokesman said: “A strategy to address serious criminal and anti-social behaviour in the garden will be agreed.
“Measures might include joint working with the police, increased security, improved lighting and expanded CCTV coverage.”
Bella Sankey, Brighton and Hove City Council leader, said: “The aim of the project is to ensure our unique and historic Royal Pavilion Garden is fit for a city and that it retains its listed status.
“This plan contains exciting proposals to restore some of the garden’s former glory as well as ensuring maximum use by residents and visitors.”
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