A group of protesters occupied a building in the centre of Bath in a demonstration against the building of bio-fuel power stations in London.
Six people from a group called Action Against Agrofuels spoke with green energy firm Blue-NG officials in Ralph Allen House in Railway Place.
Police who arrived at the premises were asked to leave by Blue-NG to allow the firm to talk to the group.
It has recently been given permission to build a generator in east London.
The plant will use combined heat and power (CHP) which is fuelled by sustainably grown crops.
Dean Rivers, one of the protesters, said: "Our intention is to force Blue-NG to look again at their position and we would like to stop the procedure of their business for today.
"They're building a whole new market for bio-fuels in combined heating power stations. They've got an application through in Beckton and they've got another one in Southall.
"They're picking these very under-privileged areas of London where there's going to be little protest and getting through power stations to be run on bio-fuels which we know are causing so much destruction globally, so we're really protesting against that."
The protesters left peacefully by 1530 BST.