Wandsworth Council are calling on protesters to quit their occupation of Battersea Park adventure playground, or face legal action.
Occupy London and members of Wandsworth Against Cuts (WAC) have been camping in the playground since Saturday in a bid to save it from demolition.
It comes after the council announced it is refurbishing the playground with new equipment, removing the need for play supervisors.
People protesting include campaigners from the borough, as well as Occupy London members from Walthamstow, Hackney and Leicester.
Since their arrival the council has closed off adjacent facilities, including a younger children's park and a one o'clock club.
The council has said they are now planning to take legal action to remove the squatters.
A Wandsworth Council press release said: "The protesters do not have any sanitary arrangements in place and could be urinating and defecating on an open site in view of children and the public.
"Any waste and filth created by the occupiers could attract rats and this could pose a risk of Weil’s disease or other rat-infestation risks.
"The protesters have also lit fires in the playground. They do not have any firefighting equipment should these get out of control and their only sources of fuel on the site are protected trees or the wooden play structures."
According to protesters, police came to the site on Monday and padlocked the children's playground, removed a petition table and locked public toilets.
But Wandsworth Council have denied this happened and the campaigners agreed to remove the table.
Colin Crilley, who was at the site, said: "People think the Occupy movement is only against the big banks and big industry, but it is filtering down to the local level causes and local issues.
"As adventure playgrounds go, Battersea is special within adventure playgrounds, it serves a mix of people both sides of the river."
Councillor Kathy Tracey said: "When it reopens later this Spring the adventure playground will offer young people a much greater variety and choice of new and exciting play equipment.
"The playground will also be able to remain open for much longer than was previously possible."