Greenpeace protesters who spent the night up a chimney at Didcot power station enjoyed a breakfast of porridge early today - and hope they do not end up eating it behind bars.

Yesterday morning, 30 activists got into the power station by walking along an internal rail line, which brings coal to the site.

Fifteen protesters chained themselves to a conveyor belt in a bid to halt coal-fired production, while a further 15 scaled the 650ft chimney.

Two then abseiled down the stack to paint "Blair's Legacy" on the side and the Prime Minister was questioned on the issue when he visited businesses in the area the same day.

This morning, Ben Stewart, 32, one of the protesters at the top of the chimney, said: "It wasn't too cold - we were quite snug in our sleeping bags and we have just enjoyed a bowl of porridge for breakfast. I hope we won't be doing porridge in a few days' time.

"We had a nice pasta meal last night and we definitely have enough supplies to last another night.

"Our people on the ground are negotiating over how long we stay here and we will listen to reason - we are open to negotiations."

Blake Lee-Harwood, 44, campaigns director for Greenpeace, who spent the night chained to the coal conveyor belt, added: "It was a bit nippy last night but everyone is very cheerful and we have had some chocolate digestives for breakfast and some tangerines, soup and water.

"I told my two children, Jake seven, and Imogen, five, that I would be back for a bonfire night display tomorrow night, but now I'm not sure I'll make it because we could still be here.

"While we are chained to this belt, coal can not be fed into the furnaces so we are preventing hundreds of tonnes of carbon dioxide from being pumped into the atmosphere.

"Protecting the environment for our children is a good motivator. My kids are already very strict environmentalists and have written to Tony Blair about car pollution without any prompting from me.

"Our long-term aim is to get a commitment from npower and the Government that they will build smaller more efficient power stations.

"But this is a totally non-violent peaceful protest and there will no confrontation with the police, who have not yet tried to get us down."

Jen Corby, a spokesman for npower, which runs the power station, appealed to the protesters to end their action.

"We are still generating power at Didcot but our major concern is the safety of staff and protesters."

Police spokesman Kate Smith said officers were still on site negotiating with protesters and added that "safety considerations" were paramount.

"Both locations are high enough to kill someone if they fell," she added.

Ms Smith said potential charges including aggravated trespass and criminal damage for painting the chimney.