The Nottingham Post reported that 48 workers have tested positive on the project being built by Taylor Woodrow Alstom.

The contractor told the Enquirer the number of positive tests was “relatively low” and said a “significant” number of those who failed were caught in pre-tests and were not allowed to start on site.

Taylor Woodrow decided to apply stricter railway toxicity tests to the civil engineering site.

A statement from parent company Vinci said: “We have a clear drugs and alcohol policy which applies to all employees and members of our supply chain.

“A tramway under construction is not classed as a railway environment but we have adopted the rail sector drugs and alcohol limits on this project.

“Tests are carried out in three stages: induction followed by random and for cause testing.

“The tests are extremely sensitive – well below drink driving levels – and anyone testing negative is removed from site for safety reasons.

“To date we have inducted c. 8500 people and the number of positive tests is relatively low.

“A significant proportion of the failures were in pre-start tests so that the individuals concerned were not permitted to start work on the site.”