RNLI reviews security after protests in Dover and Portsmouth

Speaking to BBC Newsnight, RNLI vice-president Sir Robin Knox-Johnston encouraged people abusing lifeboat crews to “have some sense about this”.

Sir Robin, a legendary sailor who was the first man to sail solo non-stop around the world, said: “The people who are abusing the volunteers – I wonder how abusive they’d be if they suddenly got a stitch when they’re out swimming?

“They’d be screaming for the RNLI to rescue them and the RNLI would do it.”

In his message to volunteers, Peter Sparkes said “at times of increased media activity like this it is only natural that members of the public, supporters, family and friends may have questions about our lifesaving work in the Channel”.

“When our crews are tasked by HM Coastguard, we will go to the aid of those who need our assistance, including those crossing one of the world’s busiest shipping lanes in small, overcrowded and unseaworthy boats,” he said.

“When called upon, we rescue people – men, women, and children – in distress.”

He said the the RNLI would then pass over responsibility for the people it rescued to the ambulance service, HM Coastguard, police or Border Force.

Figures from the RNLI show only a tiny fraction of its lifeboat launches involved assisting people “in distress in the Channel”, with the majority of small boats intercepted by Border Force.

Sparkes encouraged crew members to take measures to ensure they feel safe in their roles.

He said volunteers could do things like “choosing not to wear RNLI branded clothing when representing our charity in public places” or removing yourself from “removing yourself from a conversation with a member of public if you feel uncomfortable”.

He also encouraged RNLI members to visibly wear ID identifying themselves while on site, and to challenge anyone not wearing an ID – especially if they are acting suspiciously or trying to gain access to the building.