MILFORD HAVEN, United Kingdom (AFP) — Welsh businessman Stewart Graves is certain that a no-deal Brexit will shut down his marine renewable energy plant currently testing its prototypes in the Irish Sea.

We are world leaders in renewable technologies and that is all going to waste

The entrepreneur’s Milford Haven shipyard and its 80 workers also make sensitive communication masts that British warships will use to track enemy submarines.

Graves fears that many of these designers and engineers will soon be out of work.

“We are world leaders in renewable technologies and that is all going to waste,” Graves told AFP during a tour of his Mainstay Marine Solutions.

The possibility of a no-deal Brexit on 31 October would mean “this company will almost certainly have to go out of business,” he said.

It would mark a premature end for a leading company in a 205-year-old dockyard that has built royal yachts and warships.

Mainstay Marine Solutions and scores of other Welsh businesses depend on the help of investments from the European Union (EU).

The money is meant to spur growth in one of the poorest corners of Europe — a region whose problems pushed voters to strongly back Brexit in 2016.

Graves’s business is especially sensitive to the divorce.

Brussels has fed the plant with “match-funding” for projects harnessing the power of waves and tides into electricity that feeds directly into the national grid.

Graves always knew the EU money would dry up once Britain left the other 27 nations and doubts that London will step in when Brussels bows out.

“There is little opportunity for us to survive losing 40 percent of our business and having no market in Europe to be able to go into because of tariffs,” he said.

“If you really want to make Britain great, don’t waste it on the dogma of Brexit and leaving on 31 October.”

Britain’s business and energy department did not respond to a request for comment.

Graves works out of a dockyard that is one of 10 earmarked by Prime Minister Boris Johnson’s government to become exempt from import tariffs as a “free port” — a business-boosting idea given greater freedom outside EU rules.

Port of Milford Haven chief executive Andy Jones sees some irony in new trade initiatives emerging just as Britain is withdrawing from the rest of the Europe.

“It’s taken Brexit for the ports industry to be recognized for how important a role it plays in trade,” Jones said in his office overlooking the towering chimneys of a fuel refinery on the opposite site of the bay.

“Global trade is going to continue regardless. It’s a bit of a cliché, but we live on an island. Ninety-five percent of all trade in the UK goes through ports and that’s not going to change.”