Almost 5 million people are out of work in Britain — double the official figure, the TUC warned yesterday on the first day of Congress.

It said that the narrow official definition hides the true picture.

People are only counted as unemployed if they have looked for work in the last four weeks, are able to start a job in the next two weeks, or have been offered work but have not yet started.

The government’s 2.51m unemployment figure rises to a whopping 4.77m when the net is widened to catch those who want a job but are shut out by the official measure.

“With a further 1.4m people only able to find part-time work, despite needing a full-time job to get by, it’s clear that our labour market remains far from full health,” said TUC general secretary Frances O’Grady.

“We know that the recent fall in unemployment has been driven by short hours, low pay, temporary contracts and jobs that offer no guarantee of paid work at all.

“These types of jobs cannot form the basis for a secure and sustainable economic recovery.”

Ms O’Grady said a higher minimum wage would help reinvigorate the economy and put more tax receipts in the Treasury’s coffers.

Even a 4 per cent rise to £6.56 a hour would see the government pull in an extra £273m.

And increasing it to the living wage rate of £7.45 — £8.55 in London — would provide a boost of £3.26 billion.

“Much as we welcome wide support for the minimum wage, it is now too often an excuse,” Ms O’Grady told Congress’s opening session in Bournemouth.

“How often have we heard the boss say: ‘But we pay the minimum wage’?

“But we will never get a real recovery and sustainable growth unless consumers have cash and confidence, because that’s the kind of customers that businesses need.

“That is why this week I will argue both for a realistic rise in — and proper enforcement of — the minimum wage. The many employers who can afford it should pay the living wage.”