Climate campaigners have refused to leave a camp set up in the grounds of Cornwall Council headquarters.
The campaigners, who want Cornwall Council to drop subsidies for Cornwall Airport, defied a deadline to leave of 19:00 BST on Monday.
Martyn Alvey, cabinet member for environment at the council, said the site had no facilities and was unsuitable for overnight camping.
No-one from the campaigners was available for immediate comment.
The campaigners first set up camp in the grounds at County Hall, Truro on Monday.
Mr Alvey said: "We are not trying to stop them protesting, our concern is overnight camping, there are no facilities."
He said the campaigners had been "very well behaved" and there was "no indication of public disorder at the moment".
However, he was concerned that "less well intentioned people" could "infiltrate the group".
Cornwall Council declared a climate emergency in 2021 but in January officers apologised for not implementing an environmental decision-making policy while assessing plans for a new air service between Newquay and London.
Mr Alvey said an air link was "vital for the economy of Cornwall" and he supported the subsidy which was £3.35m last year from the council and other sources, according to the airport's accounts.
The government also said last November that it would give the council up to £1.8m over two years to run flights from London to Newquay.
Addressing some of the concerns of the campaigners, Mr Alvey said the council was "working very hard to draw in as much funding as possible to insulate houses".
Speaking on Monday, campaigner Dan Sargison from Redruth said: "We should not be subsidising flights, we should be subsidising public transport heavily."
Jackie Dash from Truro told BBC Radio Cornwall: "Cornwall has some of the most poorly insulated homes which means that the energy that's used to heat our homes is drifting out of the walls.
"I'm a pensioner and I'm really struggling to keep up with my energy bills, so we need to invest strongly in green technologies."