Women should have the right to know what their male colleagues are paid if they suspect wage discrimination, said a charity for gender equality.
The Fawcett Society is calling for a change in the law to try to reduce the cases of unequal pay.
But men can help by simply telling colleagues what they are earning, the charity added.
This call comes as unions pledge to fill the pay gap between men and women by 2030.
Sam Smethers, Executive Director of the Fawcett Society, said: "Payment secrecy means that women can not know if they are being paid equally and fairly.
"Even though they suspect that a man is gaining more, it's almost impossible to do anything about it.That's why we're calling for a change in the law."
She said that women need a "right to know" that is enforceable so that their colleagues earn in order to fight unequal pay.
"Men can help by simply telling their female colleagues what they're earning – it's as simple as that," added Ms. Smethers.
Shanti Kelemen, chief investment officer at Brown Shipley, told the BBC Radio 4 show that she should be "all or nothing".
"I just think that giving women the right is not the answer, why not minorities, the elderly, the young?"
"If I had to implement something like this, use a system like Sweden where everyone can view the tax return from anyone. The problem is that everyone will know that you consulted. "
Under UK law, men and women are expected to receive the same pay for comparable work.
The Fawcett company 's call comes after the Labor Party promised to fill the pay gap between men and women by 2030 when it won the election.
The pay gap between men and women is the percentage difference between the average hourly earnings of men and women.
"I feel betrayed and disgusted"
Kay Collins worked for a restaurant business, but her professional life began to deteriorate after a chance conversation with a colleague in September 2015.
She discovered that he was earning £ 6,000 more per year for having fulfilled exactly the same role as a chef.
"I was shaking, I was so angry," she says.
She was older and more experienced than her colleague and therefore grieved her female supervisor.
However, his manager stated that the man had more responsibilities, although he himself declared it.
He eventually resigned and Kay lost her job, although she got a settlement in court after a process that took many years.
"It was a test, that was it," she says. "I lost two stones in a few years [because of the stress]. "
However, the settlement was not enough to cover his £ 15,000 legal costs.
Kay, who is 60 years old next year, has felt "shot down" afterward. She is now working full time with her husband, William, who suffers from heart problems and still has to work from home to pay his mortgage.
"I feel disgusted and betrayed."