More than 1,500 have taken part in the Climate Camp in Kent
Activists have started leaving the Climate Camp near Kingsnorth power station in Kent.
About 1,500 people have been stationed at the site, which is about two miles from the power plant on the Hoo peninsula, for the last week.
They have been protesting against E.On's plans to build new coal-fired units.
On Saturday they held a day of action which saw 50 activists arrested and 123 taken out of the River Medway.
A handful of people breached a security fence, but E.On spokesman Jonathan Smith said they had no effect on the power station.
Climate Camp organisers said the past week had been a great success in increasing people's awareness of the threats of climate change and alternative means of power.
Spokesman Terry Graves said there would be a meeting about where the campaign goes "from here in the context of Kingsnorth".
"People are really keen to come and keep the campaign going."
He added: "A number of people have started to leave [the camp] but a number of people will stay on to make sure the site is in a perfect condition when we leave."
Mr Graves said the number of people on the site would shrink to about 20 by the end of the week.
He added: "We take this really seriously... we are not going to just abandon a field to the rubbish."
On Saturday a group of about 100 campaigners, some carrying drums and banners, marched from the camp to the power station.
And up to 30 rafts took to the River Medway as part of a river protest against E.On's plans, according to a climate camp spokeswoman.
The current Kingsnorth power station is due to close in 2015 and E.On wants to replace it with two new coal units, which it claims will be 20% cleaner.
Its proposals, which would see the first new coal-fired power plant being built in the UK for 24 years, have already been approved by Medway Council but the government will make the final decision about the project.
Activists have vowed to return to the power plant if the decision is approved.