A group of Greenpeace activists has been arrested after an hours-long protest on the roof of Rishi Sunak’s mansion over his new fossil fuel drilling “frenzy”.

Campaigners draped the Prime Minister’s grade II-listed manor house in North Yorkshire with an oil-black fabric to “drive home the dangerous consequences” on Thursday – in action that was criticised by the Conservatives and Labour alike.

Police had been “managing the situation” after being alerted to the activists climbing the family home in Kirby Sigston, near Northallerton, at about 8am, while Mr Sunak, his wife and children were on holiday in California.

The group returned to the ground at about 1.15pm and were being spoken to by officers before being loaded into the back of police vans.

North Yorkshire Police said two men and two women had been arrested on suspicion of causing criminal damage and public nuisance. A fifth man was later arrested on suspicion of causing public nuisance.

Assistant Chief Constable Elliot Foskett said: “There was no threat to the wider public throughout this incident which has now been brought to a safe conclusion.”

But a former deputy chief constable from the force said it was a “major breach of security”, as he called for an “investigation into how this has been allowed to happen”.

Mr Sunak, the MP for nearby Richmond, this week announced plans to “max out” the UK’s oil and gas reserves by granting more than 100 new licences for extraction in the North Sea.

He also hinted that the UK’s largest untapped oil field, Rosebank, to the west of Shetland, could be approved despite fierce opposition from environmental campaigners.

Climate-conscious Conservatives have joined campaigners to warn against the move, amid concerns it will hinder efforts to reach net-zero by 2050.

After scaling the house with ladders, the four activists unfurled the black fabric and brandished a banner demanding “no new oil” as they urged Mr Sunak to “be a climate leader, not a climate arsonist”.

Protester Alex Wilson, who lives in Newcastle with her partner, who was also on the roof, released a video message from on the roof of Mr Sunak’s house.

“We’re all here because Rishi Sunak has opened the door to a new drilling frenzy in the North Sea while large parts of our world are literally on fire. This will be a disaster for the climate,” the climber, originally from East Yorkshire, said.

On the ground, Greenpeace UK climate campaigner Philip Evans defended the action at the Prime Minister’s family home.

He told the PA news agency the group had knocked on the door when they arrived and said “this is a peaceful protest”, but there was no answer.

Asked whether it was intrusive to target someone’s home, Mr Evans said: “This is the Prime Minister. He is the one that was standing in Scotland going to drill for every last drop of oil while the world is burning.

It is clearly in my view a major breach of security

“He is personally responsible for that decision and we’re all going to be paying a high price if he goes through with it. It is personal.”

Peter Walker, who stepped down as North Yorkshire Police’s deputy chief constable in 2003, said he was “absolutely astonished” the protesters gained access to the house, as he called for an investigation.

He told LBC radio: “It is clearly in my view a major breach of security.

“If free access is being granted to that property, people who wanted to do much more serious things would be able to leave devices or booby traps or something like that, and I really think this is a major failing, and it grieves me to say it because it’s my old police force that has failed.”

Deputy Prime Minister Oliver Dowden, who is standing in for Mr Sunak during his holiday, told the protesters to “stop the stupid stunts”.

Speaking on a visit to Able Seaton Port in Hartlepool, he said: “I think what most people would say is ‘can you stop the stupid stunts’, actually what they want to see from Government is action.

“That’s what you’re seeing here today, the world’s largest offshore wind farm being built right here, creating jobs.

“But at the same time we’re going to need in the coming decades oil and gas as part of our energy mix.

“The question is do we produce it here, where we get more tax, we create more jobs, or do we do what the Labour and others say which is say ‘no more investment in our North Sea oil and gas’?”

Labour’s shadow home secretary Yvette Cooper said: “Targeting someone’s home like this is disgraceful and totally unacceptable. This is against the law and rightly the police are taking enforcement action.

“The Prime Minister’s home and family should never be targeted in this way.”

Government minister Alex Burghart called the activists “plonkers”.