Nine climate change protestors who scaled Didcot Power Station’s 200-metre-high chimney returned to earth today after two days.

The five men and four women abandoned their sit-in at 4am, almost 48 hours after they had broken into the plant and used an angle-grinder to cut their way into the chimney’s entrance.

The nine were arrested as they gave up their protest, which started at 5am on Monday when the group cycled through open security gates.

Eleven other activists, who had chained themselves to the conveyer belt carrying coal into the power station’s furnaces, were arrested on Monday evening after a five-hour police operation to cut them loose.

Throughout the occupation, the power station continued to run.

The protestors atop the chimney had pledged to stay for as long as possible, claiming they had food and water to last a week.

The police had said it was too dangerous to go up to arrest them, instead waiting for them to give up.

Site owner RWE npower obtained a legal injunction allowing them to remove the trespassers.

On Tuesday, it had considered sending up security guards to remove them, but concluded it was too risky.

Npower spokesman Claire Loveday said: “They obviously came down of their own accord, and they had said various different things about their intentions while they were up there. We’re just relieved that they are down safely.

“We’re already upgrading our security at the site, and that will include reinforced physical defences and greater staff numbers.

“The upgrading will include greater security at the gatehouse which was the focus of this break-in. We will review the situation in detail with the police to see what lessons can be learnt.”

One of the protesters, Joanna Bates, 21, from Leeds, said: “We cycled through the gates, past the security guards.

“They kind of just looked up 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.”

But power station manager John Rainford claims the group overpowered staff, forcing them to the ground.

It is the second time in three years that the coal-powered Didcot A station’s chimney has been occupied.

In November 2006, Greenpeace activists daubed “Blair’s Legacy” on it, and the power station recently invested in a new fence around the site to improve security.