"We welcome the work by operators, manufacturers and industry safety groups to engage with the offshore workforce to address its concerns about Super Pumas," the parliamentary Transport Select Committee said in its report on offshore helicopter safety.

"However, we heard troubling evidence about a macho bullying culture in the oil and gas industry, including that offshore workers who were concerned about helicopter safety were told that they should leave the industry.

"We believe that more must be done to facilitate a culture of approachability and openness at all levels."

These views were not supported by Oil & Gas UK Health and Safety director Robert Paterson.

"We have yet to see any evidence of the unsubstantiated allegations concerning improper commercial pressure affecting safety outcomes which are repeated in this report," he said.

"It is vital that everyone plays their part in keeping the workforce safe and if anyone has evidence of commercial issues overriding good safety practices, they must report this immediately."

There have been five accidents with Super Puma helicopters in the North Sea over the past four years, with the last one killing four people in August 2013.