The government may call on companies to confess how many of their workers are being paid less than the living wage, it was announced yesterday.

Business Secretary Vince Cable told MPs the idea, originally put forward by Labour, was an interesting suggestion for "nudging companies in the right direction."

But Mr Cable attempted to talk down union proposals for mandatory annual reports, saying he was against "coercive measures" which he claimed would risk increasing unemployment.

Employers can voluntarily opt to pay the living wage, which is calculwated to meet the basic cost of living in Britain.

The rate is currently £8.80 an hour for London and £7.65 for the rest of Britain, compared to the minimum wage of £6.31 an hour for workers aged 21 and over.

Speaking during business questions, Labour MP Heidi Alexander told Mr Cable: "The UK's largest supermarkets - Tesco, Sainsbury's, Asda, Morrisons - together make billions of pounds in profit every year but they still don't pay all their staff a living wage.

"Will you look at amending the corporate governance code to require all publicly listed companies to report annually the number of individuals they employ who earn less than a living wage?"

Mr Cable replied: "That is an interesting suggestion for nudging companies in the right direction.

"I will certainly have a look at it. I'm certainly very opposed to coercive measures, because these would simply add to unemployment - but I will reflect on that suggestion, which is a new one."

TUC general secretary Frances O'Grady welcomed serious consideration of the matter but said the practice should be mandatory.

She said: "Company pay structures are still shrouded in secrecy. Forcing businesses to be more transparent about how staff are paid would shine a light on companies who rely heavily on poverty wages, or who pay women less than male staff."