Bosses at Glasgow’s once-thriving shipbuilding yards were stern about keeping workers on a short leash. With more workers than jobs, misbehaviour, however minor, was not tolerated.

But as the industry has disintegrated, so has the plentiful supply of staff.

Ferguson Marine is the only yard left on the Lower Clyde, about 20 miles northwest of Glasgow. Nationalised by the Scottish government in 2019, opponents of Nicola Sturgeon say the business stands as a shining example of everything that is wrong with the First Ministers’ economic policies.

Criticism has, until recently, focused on the yard’s financial trevails. That it was run by an executive who was paid more than the boss of HS2, England’s highest paid public servant. That a slew of building delays means the decision to take Ferguson Marine into public ownership could end up costing UK taxpayers £300m.

But the Telegraph can disclose another plight facing the 119-year-old business. In recent months, drink and drug problems appear to have reared their head again.

During a random test in November, nine of its staff members tested positive, according to a freedom of information request. One was later found to be a false positive, the other eight staff were sacked. It was not specified if the results were for drugs or drink.

A spokesman for the Scottish government says: “Given the nature of the work undertaken by Ferguson Marine, these findings are clearly alarming and could potentially compromise workers’ safety.”

Former owner and billionaire Jim McColl says: “A lot of people left when the Government took over the yard. They got rid of a lot of the senior management and a lot of the good people below that.”

“I suspect that in the push to get people back in to restart the yard, they probably let back in some of the bad elements that we let go.”

When McColl bought Ferguson Marine in 2014, he was warned about the yard’s drinking culture. The answer was to bring back a stricter approach to labour relations. A manager at the time suggested shortening the lunch break as some workers went to the pub.

“The whole goal was so that they didn’t have time at lunchtime to go to the pub and come back in the afternoon with drink in them,” he says. “So we reduced the length of the lunch break.”

Begrudgingly accepted by staff, the trick seemed to work. But by 2015, matters had turned more sinister. 

“We didn’t have any problems after that until both of the union representatives said that we had a particular challenge with a group. I think it came down to a particular person. And it was related to drugs,” says McColl.

“We immediately put in a drug and alcohol policy and we did [testing] and removed the people concerned.”

“Once that was done we didn’t have a particular problem. I think it was a bad element and came down to one or two individuals that we took through disciplinary procedures and dismissed.”

Fast-forward to 2019 and Sturgeon made the controversial decision to seize control of the business from McColl, a one-time ally, government adviser and supporter of Scottish independence. McColl continues to contest the nationalisation and has pledged to take legal action against Holyrood.

The more immediate problem, however, is that the tests carried out in November – the only one since the SNP took control – show Hair has failed to stamp out drug and alcohol use. It has raised concerns among politicians. 

Scottish Conservative Shadow Justice Secretary Jamie Greene says: “Shipbuilding is an environment where safety is absolutely critical and the health and safety of employees should always be a top priority.

“Further evidence of drug or alcohol abuse should be a cause of concern for management, who I hope now investigate this matter urgently and support those who need it.”

A Holyrood spokesman responds: “The Scottish Government has been given an assurance by the yard that appropriate procedures are in place to investigate and handle personnel matters like this.”