CLIMATE protesters who scaled Didcot Power Station’s chimney said they broke in by riding past security guards on bikes.

As the Oxford Mail went to press, nine campaigners were preparing to spend the night on top of the 200-metre-high stack, saying they had enough food and water to last a week.

Police said it was safer to let them stay up there than to remove them in the fading light.

Eleven activists who chained themselves to the plant’s coal conveyer belt were arrested and charged with aggravated trespass after a five-hour operation to cut them loose.

Fifty officers were called to the RWE npower-run station, which continued to operate throughout the raid.

The 20 protesters arrived on bicycles at 5am, using an angle-grinder to cut their way through a door into the tower, and climbed steps to the top.

Station manager John Rainford said: “We were opening the main gates for our normal shift changeover. All of a sudden, 20 individuals on bikes came through and overpowered the security people on the gate.

“We’ve got reports of our security staff being physically manhandled and forced to the ground at both the main gate and the gate to the chimney.”

But climate protesters on top of the chimney said Mr Rainford’s claims were “nonsense” and there had been no physical altercation.

Joanna Bates, 21, from Leeds, said: “We cycled through the gates, past the security guards. They kind of just looked at us and said they thought we must be going the wrong way.

“We said: ‘No, I think this is the right way’ and carried on. Just as we were entering the chimney they came over and tried to stop us, but we all got in.”

Amy Johnson, 20, of Cowley, said the protesters had enough water and dry food for a week.

Going to the toilet was “a complicated process involving funnels”, she said.

The activists claim RWE npower wants to build a new generation of coal-burning power stations. The company says clean coal technology is part of the mix to provide future electricity.

Last night, Ms Johnson said: “We’ll definitely be up here at least until tomorrow. The police haven’t made any move to come up. It would be possible, but I think we’re here until we decide to come down.”

Mr Rainford said security would be reviewed following the second breach in three years. In November 2006, abseiling Greenpeace protesters daubed ‘Blair’s Legacy’ on a chimney after breaking in.

Mr Rainford said: “We’re in the process of upgrading our security and we’re not quite there yet. It is always difficult to defend a location like this.”