By Richard Wells
BBC News, Drax Power Station
The demonstration at Britain's largest coal-fired power station in North Yorkshire has put the spotlight on carbon emissions and is proving a challenge to police.
This has been a largely good-natured, though noisy demonstration, but it has been a very difficult one to police.
The protesters will be camped near the power station until next week
When they arrived here a week ago, the protesters said they would attempt to close Drax Power Station down and that is what they have been trying to do.
The company running Drax took out an injunction which should prevent anyone getting within two miles of the perimeter - but that has been flouted.
The protesters are playing a cat and mouse game with police, who have brought in horses and a helicopter to try to keep tabs on them.
Police in fluorescent jackets have been patrolling the perimeter fence. The protesters are being heavily policed, with reinforcements not just from Yorkshire but also the Metropolitan Police, who have travelled more than 200 miles to try to keep the power station secure.
The biggest problem facing them is the scores and probably hundreds of protesters who have abandoned the country lanes and instead evaporated into the woods and fields, trying to scale the perimeter fence to get inside and stop production.
Protesters have been saying Drax is the dirtiest power plant in Britain.
"Climate change is an issue nobody can ignore and Drax should be shut down immediately", some said.
"History will spit on us," reads one banner being carried by protesters: "Save the climate, save the planet..." reads another.
The protesters' aim was to stop production at Drax
Hundreds of protesters have gathered outside the plant's entrance. Some have blocked the main road.
For the moment, the police seem happy to sit there and let them do that.
While the protesters were there on one side, earlier there was also a group from the GMB union - who have members at the plant - and from the Yorkshire Energy Forum, who have been putting the case for coal.
The forum's chairman, David Bowe, said climate change was something they were concerned about, but they believed technology making coal cleaner would provide an answer to the concerns of the environmentalists and the general public.
The relationship between the police and the protesters has ebbed and flowed.
There was heightened tension at the entrance to the protesters' eco-camp when some tried to get out and were stopped by several lines of police officers.
There was a stand-off for about an hour, tempers cooled and the protesters were allowed to walk along the country lanes through a village and then down a road somewhere nearer to the site.
But less than 300 yards down they were stopped again and angry noises were heard.
When protesters move onto the fields, problems start for the police as they have to keep tabs on people hell-bent on trying to get into the plant.
The company says the protesters are putting themselves and those who work here at risk.
It says it understands why people protest, as coal is a dirty fuel, but that it is doing its best to keep it as clean as possible.
The plant produces an enormous amount of electricity - 7% of Britain's electricity needs at any one time - and as a consequence produces 20 million tonnes of carbon emissions each year.
The company says it is working with government and European agencies to reduce carbon content, but can't have people running around the plant trying to stop production.
That would be against their interests, those of the protesters and power consumers, it adds.
But irrespective of what the company is saying about clean-coal technology and their efforts to reduce carbon emissions per unit of electricity produced, the protesters say it is still too dirty.
They say we should be moving away from coal-fired power stations to renewable energy and the country as a whole should be producing and using less electricity.
Their aim is to heighten awareness of coal-fired power stations, energy consumption and the polluting effects of coal when it is burned in a power station.
The camp opened for business last Saturday and the publicity the protesters have got from then has been manna for them.
Dozens of protesters have been arrested so far for offences including possession of offensive weapons and causing a public nuisance.
Thursday is the focus of the protest but they say they will stay until next week.