When five activists who brought chaos to the M25 motorway were jailed last week, some thought the law had finally caught up with Just Stop Oil.

Celebrities spoke out in anger at the lengthy sentences - and a United Nations official described their treatment as “not acceptable in a democracy”.

With Roger Hallam, the architect of the modern environmental protest movement, and his co-conspirators now behind bars, this might have been “checkmate” in a five-year long game of legal chess between the state and a group of increasingly bold direct action environmental groups.

But at least for some Just Stop Oil (JSO) activists, it doesn't appear to have worked.

On Wednesday ten of them were arrested at Heathrow Airport after a suspected plot to block the runway was foiled at last minute.

That shouldn’t come as a surprise, because getting jailed was always part of the strategy for JSO. It is one of the first things that new joiners are asked: would you be locked up?

Speaking to the BBC exclusively in a recorded message from his prison cell this week, Hallam stood by his actions.

“The strategic moral imperative is resistance to the greatest [crisis] in the history of humanity”, the JSO co-founder said.

Direct action remains “the right strategy”, he added, confident that while in the short run some people may be deterred, others will only grow more determined.

It begs the question of what Just Stop Oil is planning next - and whether they're about to outpace the law once again.