An environmental activist planning to take part in the Great Climate Swoop at Ratcliffe-on-Soar coal power station this weekend has been arrested today on suspicion of conspiracy to commit criminal damage, a crime which can carry a maximum sentence of 10 years.

The action by police follows the recent charging, which I blogged about this week, of 25 other activists with conspiracy to commit aggravated trespass. It also comes after the use of antiterrorist legislation to prevent Chris Kitchen from travelling to Copenhagen, where he had planned to work with activist organisation Climate Justice Action, which is planning demonstrations during UN climate talks in December.

The latest arrest will worry environmental activists, who suspect that police are now casting aside heavy-handed techniques such as the "kettling" used during the Kingsnorth and the G20 protests in favour of a more preventative approach.

This was attempted a couple of years ago, when lawyers applied for an injunction under the Harassment Act to keep Climate Camp away from Heathrow, but the attempt was unsuccessful, and only three individuals were prevented from attending the camp. However, conspiracy charges might be more successful as a deterrent as they carry the possibility of heavy sentences, and conditions that prevent suspects communicating about the case with friends, family or colleagues.

Lawyer Lydia Dagostino, who has represented activists on similar charges said: "There will be three main purposes to this charge: firstly to pick out the key people involved in the action on Saturday and to get rid of them, secondly to impose heavy bail conditions which will prevent them from communicating with their friends and with other organisers, and thirdly to put people off coming along on Saturday."

One activist told me she suspected that Climate Camp would now move away from its usual tactic of announcing targets in advance and begin working more covertly like many other direct action groups.