A climate activist who invaded the track at last year's British Grand Prix told a court on Wednesday that the protest was safe due to its meticulous planning.

Louis McKechnie, 22, and five other Just Stop Oil activists are on trial accused of posing a risk of serious harm to F1 drivers and marshals after they invaded the Silverstone track in central England last July.

But he told Northampton Crown Court that the group had carefully planned the stunt so that they would enter a section of track with clear sightlines, at a time when cars were moving slowly due to a crash.

McKechnie, 22, denies a charge of causing a public nuisance by sitting on Silverstone's Wellington Straight before he was dragged away by a marshal.

"It started off as Zoom calls and group texts and sometimes in-person meetings," he told the court of the planning phase.

He read the Formula 1 rulebook and watched "every single race that's been held at Silverstone over the last 20 years".

"I scoured the internet for every piece of information I could get about the track, the red flag system and also the drivers.

"We picked a part of the track which would give the cars plenty of time to pass where we were, before we went on."

McKechnie waited until there was an obstruction on the track, and until a red flag was subsequently waved to tell the drivers to stop racing.

"I knew I was safe and secure where I was on the track. I understood that where I was would be perfectly fine."

McKechnie said the group was demanding a "just transition to renewable energy".

Since the Just Stop Oil campaign began nearly a year ago, there have been more than 2,000 arrests and 138 activists have spent time in prison, according to the group.

On Tuesday, two Just Stop Oil protesters were ordered by a London court to pay compensation to the Madame Tussauds waxwork museum, after attacking an effigy of King Charles III with vegan chocolate cakes.