A third of British workers would turn a blind eye to illegal or dangerous activity by their employer through fear of the repercussions, research by Manchester solicitors has revealed.

More than 50pc of respondents in a survey by Manchester employment law specialists Slater and Gordon said they would keep quiet if bosses were up to no good because they would be scared of losing their job.

Others said they would fear how would be treated by colleagues after coming forward - and if they’d even be believed.

But research revealed that the number of people who would consider blowing the whistle rose to 67pc if they could complain anonymously.

North West Trades Union Congress regional secretary, Lynn Collins, said: “These figures are worrying. Workers should be supported in speaking out about illegal or dangerous practices – after all it isn’t likely to be for their own benefit that they would speak out.

“The statistics show us that the balance of power in a workplace is tilted in favour of the employer and that should be tackled.

“This underlines the need for strong trade unions in the workplace. Where unions are present in work, they can ensure whistle blowers are protected and supported.

“Policies on such matters are often in place in unionised workplaces. It’s also likely that such practices would be raised by trade unions present in the workplace on behalf of their members, giving workers a voice on such issues.”

The study of 2,000 workers showed almost half - 49pc - said they would come forward if they had legal protection from being mistreated and would get financial compensation if they were sacked. And 17pc said they would speak out if there was a cash reward.

A quarter said they would keep quiet out of loyalty to their employer - and more than a fifth said they would feel it wasn’t any of their business to speak out.

Results revealed that 16pc of people had spoken out, with almost half of those exposing health and safety breaches. Some 29pc said they had raised concern over illegal activity.

Over half of those who had exposed wrongdoing said they were treated differently after coming forward, with 30pc saying they were constantly criticised by their boss.

And one in 10 were fired or made redundant after speaking out.

One respondent said they had reported colleagues who drove trains for smoking cannabis at work. Another raised concerns over a doctor who was secretly filming patients.

Other examples included employers avoiding tax; document forgery; stealing; witness harassment; and bullying.

Employment lawyer Samantha Mangwana said: “It is alarming that a third of people are scared to come forward and expose even the most serious wrongdoing at work because they are concerned about the repercussions.

“The fact that a large percentage of people said they wouldn’t speak out, even if they saw the law being broken, illustrates just how worried people are about what will happen to them if they do.

“It takes a lot of bravery to blow the whistle, but it needn’t be as terrifying as some people seem to think as long as they get the right legal advice.

“Being able to remain anonymous would make a big difference to employees’ thinking when it comes to speaking out, while a lot of people said they would blow the whistle if they would be protected.

“Our research shows most people don’t know that there are laws in place to protect whistleblowers - 63pc.”