A Climate Camp protest took place in Heathrow in 2007
Green activists have refused to reveal the location of a planned protest camp despite police requests, saying they "just don't trust" the police.
Some 3,000 people are expected to attend Climate Camp's seven-day protest at a secret London location next week.
Metropolitan Police asked organisers to tell them the location to enable police to smooth relations with residents.
A Climate Camp spokesman said the "best thing" police could do would be to "stay as far away from it as possible".
The Met faced widespread criticism of its handling of the G20 summit in April, which included a Climate Camp protest in the City of London.
The G20 demonstrations were marred by the death of newspaper vendor Ian Tomlinson. The Crown Prosecution Service is considering whether any criminal charges should be brought.
Assistant Commissioner Chris Allison urged Climate Camp to reveal the location of next week's protest, where he said "community-style policing" would be carried out.
Mr Allison added: "A fundamental bit of policing is understanding where it is going to be and when it is going to take place because of the impact they will have on people around them."
Climate Camp responded in an open letter to Met Ch Supt Ian Thomas, saying police would discover the camp's location at the same time as the group's supporters, on 26 August.
"There's a simple reason for this: I'm afraid we just don't trust the police," Climate Camp organisers wrote.
"Why? Because it seems as though every time we have a protest, the police turn up and start hitting people.
"Look what happened at the G20. That's not really a very good way to win people over."
Climate Camp said community liaison was a "vital part" of its previous protests, including camps it set up at Heathrow in 2007 and Kingsnorth, Kent in 2008.
Ch Supt Ian Thomas said the Met was "very disappointed" by "unhelpful comments" in Climate Camp's letter and added it was "highly irresponsible" of the protesters to keep the location secret.
"Without advance knowledge it is impossible for us to liaise with a local authority or local community as we don't know who to liaise with," Ch Supt Thomas said.
"For us not to ask for the location would be negligent given our duty to provide a proportionate policing response to protest and minimise the impact on Londoners who wish to go about their business as normal."