The council plans to start working on the Herne Hill junction in April, which involves asphalting over 1,070sq m of parkland.
The Friends of Brockwell Park (FBP) group is picnic-protesting and sent a 300-signature online petition to mayor Boris Johnson, asking him to delay the start while its alternative proposal and the council's are "fairly and independently evaluated". FBP chairman Laura Morland said: "Parkland is our children's heritage and to lose it unnecessarily is criminal. We call on Lambeth Council to respond honestly to the mayor's requirement for an independent evaluation of both schemes."
The FBP is submitting an alternative planning application commissioned from traffic engineer IMA that uses only half the parkland.
Lambeth Council's planning committee approved the plan to change the road layout next to the park's Herne Hill entrance to reduce traffic jams last March.
- See www.brockwellpark.com