Hundreds of fishermen face losing their livelihoods because of new rules that will brand them too fat to fish.

UK Government regulations which are about to come into force will mean seafarers must have a medical certificate showing a body mass index (BMI) of under 35 – or risk being banned from their own trawlers.

Crewmen fear they will not be able to go to sea because of the draconian requirements. Furious fishermen branded the Maritime and Coastguard Agency (MCA) rules “discrimination”. Bob Dunsire, 49, who has been skippering prawn boats out of Pittenweem, Fife, since he was a teenager, said he can barely believe what is being done to the industry.

He said: “I know I don’t have a BMI under 35 and I’m furious at these new medical requirements. They could see me out of my job and put my entire crew out of work, too. I started fishing when I was 13 and have been a skipper from the age of 17. It’s all I know. It’s my life and I’ve had no significant incidents at sea. It’s discrimination, pure and simple – you wouldn’t get it in any other industry.

“Fishermen operating on small boats have been through one of the toughest few years I can remember. The pandemic brought us to our knees because all our markets disappeared. The toll it took on families and mental health was enormous. Now, just as we are trying to get back on our feet, we’re hit with this bulls**t.

“We had Brexit and were told by Boris Johnson we would be taking back control of our waters and our fishing industry, and getting rid of the stupid rules and regulations. Now he’s gone and we’re hit with this. It’s clear nobody has a f*****g clue what they’re doing and small boat fishermen are going to suffer.

“The big trawlers will be OK as they’ve been working for the last few years to get into line. It’s the small boats that nobody seems to care about and a lot of lives and communities could be affected.” The engaged dad-of-three added: “We are human beings but are being treated like bargaining chips by the Government. You have about 20 boats operating out of Pittenweem.

“I reckon there will be a few guys on each boat that could be affected. There are hundreds of fisherman around Scotland really worried about this and it’s time someone listened.”

Officials claim the new rules will help reduce the risk of accidents at sea. International fishing convention regulations were adopted by the UK in 2018 but the Government allowed five years for workers to obtain medical certificates, which now must be in place by November 30.

In some cases fishermen say they have been told they must get below the required weight within a year or stop working. A get-out clause, called “Grandfather Rights”, can be granted in some circumstances for pre-existing conditions but they are not guaranteed.

BMI is calculated on height and weight with anything over 30 considered “obese”. A 50-year-old man who is 17.5st and average height would likely have a BMI over 35.

Sarah Ready, of the New Under Ten Fishermen’s Association, said: “These new rules are discriminatory and it feels, at times, like the Government is trying to decommission boats by stealth. Every year they are making it harder to operate. The new regulations and the BMI requirements don’t make sense.

“Many fishermen tend to have a bit more weight on them. It’s a physically demanding tough job and they tend to be heavier and more muscular. Many members of the Scottish rugby team will have a BMI over 35. We’ve had reports of people saying they’ve been given Grandfather Rights for a year but told to lose weight within that time. It’s inhumane and insulting.

“There are more than 4000 fishermen in Scotland and a third could be affected – that’s more than 1000 people. It’s going to hit small communities where fishermen have already been struggling to keep their traditional way of life alive.”

The MCA has said overweight fishermen may be able to claim “Grandfather Rights” that will allow them to continue working even if they don’t meet BMI requirements.

But the agency said these will only be “considered” if the applicant is deemed to be able to work “without significant risk to your own or others’ health and safety”.

The agency added anyone who does not apply for a medical certificate before November will not be eligible for Grandfather Rights. Thousands of fishermen are still to get a medical certificate and industry leaders warned many are struggling to get an appointment with a GP in time.

Alistair Carmichael, Scottish Liberal Democrat MP for Orkney and Shetland, said: “A few years ago you couldn’t move on fishing ports for Tory ministers promising the Earth to fishermen.

“These promises were broken and now Tories in fishing communities have gone into hiding. They’ve delivered a botched Brexit deal that broke just about every promise they had made, introduced a visa scheme that has boats tied up in port as they can’t get crew and now they are playing nanny for people who do some of the most physically demanding work to be found anywhere.

“Fishermen are right to be angry and to feel insulted. The only scales they should have to worry about are the ones on the fish they catch.”

Western Isles MP Angus MacNeil added: “This is just baffling and smacks of bureaucrats desperately trying to justify clipboard jobs. Fishermen are usually quite muscular and as muscle it heavier than fat they can’t be compared to office-bound clipboard man.

The MCA said: “Introducing medical certificates is not to prevent existing fishermen from working. We are supporting and preparing fishermen in the lead-up to this requirement coming into force. We’ve made sure Grandfather Rights are in place, which considers pre-existing medical conditions.”