Occupy London: A street-level view guardian.co.uk

Anti-capitalism activists camping outside St Paul's Cathedral have denied press reports that only 10% of their tents are occupied at night, and police said they were not the source of the figure.

The Occupy the London Stock Exchange protesters, who moved to an area at the front of the cathedral 10 days ago, say allegations that the majority of them are abandoning their tents each evening to sleep elsewhere are untrue.

"OccupyLSX was surprised to hear the Telegraph and others reporting this morning that 90% of our tents are empty overnight," the group said in a statement.

"This is simply not the case. While it is quite possible that not every tent is occupied every night, we try to keep vacancy to a minimum and operate a sign-in/sign-out system to help ensure this happens. The camp attracts thousands of people every day. We do not expect all the people who are expressed through this movement to be able to stay overnight."

Reports quoting the 10% occupancy rate appeared in the Times, Telegraph, Sun, and Daily Mail on Tuesday, apparently based on evidence gathered by a police helicopter equipped with thermal imaging cameras.

However, City of London police told the Guardian that they could not confirm nor deny the reports, saying only that neither details of the thermal imaging cameras nor the occupancy estimates had come from them.

"As you'd expect, we'd use a range of techniques to facilitate peaceful protest but we wouldn't comment on the specifics of how intelligence is gathered," said a spokesman. "We haven't commented on numbers from the outset.

"We've no idea where this has come from but the point is it hasn't come from us. We haven't commented on this."

A local councillor quoted in the reports said he had been told about the thermal camera by a City of London officer on Monday, but admitted he had not been able to verify the "second-hand" information.

"I simply heard it from talking to an officer on the street," said Matthew Richardson, councillor for the Coleman Street ward. "The summary was that they have got a helicopter with a thermal camera in and only 10% of the tents are occupied."

Several of the protesters outside St Paul's admitted they were not staying at the camp full-time, but they disputed the occupancy allegations.

"This 10% figure is bullshit," said one camper, who did not wish to be named but said he was from Birmingham. "It's closer to 70% occupancy. People who live locally are going to their homes to sleep, but the rest of us generally sleep in our tents."

Another camper, from Bristol, said many of his fellow demonstrators were working people, rather than students or professional protesters, who were trying to balance their jobs with their activism. That meant, he said, that they sometimes had to leave the camp.

"People have to juggle between days when they're working and days when we're here," he said. "I'm self-employed. Most of the people are here because they're choosing to be here. Most of the tents are left open for other people to use."

Robin Smith, a 48-year-old former Conservative councillor for Wokingham town council, said he was one of many part-time protesters at the camp.

"I'd say about 25% of the people go away and come back. There are lots of normal middle-class people turning up and helping but they have to go back home and some people come once and go away," he said.

"They've got jobs and a family to keep, so they've got to look after their kids or go to work. I met one guy who comes in then goes home to go to work."

The City of London Corporation told the Guardian that Richardson was not one of its official spokespeople.

"The City will accommodate lawful protest but this should not involve a long-term campsite that blocks the highway," said Stuart Fraser, chairman of the corporation's policy and resources committee. "We hope common sense will prevail and those camping around the cathedral will recognise that they are damaging the integrity of their protest by their actions – and they decide to disband in a peaceful manner."