Thousands of driving tests were cancelled in the UK earlier last month after transport department staff went on strike.

The reason for the industrial action? Comparatively low pay among a mostly-female workforce in a Government department.

How did they know they were being underpaid? The Freedom of Information Act.

During a row in which workers were complaining about a series of below-inflation wage offers, the Public and Commercial Service Union decided to make use of FOI legislation to compare the pay of workers in different departments.

It learned that the Driver and Vehicle Licensing Agency — which has a mainly female staff — was being underpaid $17.5 million a year compared with colleagues on the same grades elsewhere in the Department of Transport.

On February 29, 5,000 tests were cancelled after the up to 8,500 workers called a strike out of support.

Their fight for equal pay is continuing this month, with general secretary Mark Serwotka telling the British media on International Women's Day: "The government need to address the gender pay gap, especially in its own workforce where pay inequality is rife.

"It is a situation which is being made worse by low pay and its policy to drive down wages.

"If the government is to meet its responsibility to tackle the gender pay gap then it needs to start with its own workforce by ensuring departments conduct equal pay reviews and by setting aside the resources to tackle low pay and pay inequality."