The TUC warned against slumping wages this morning after a report for the union body showed most people on zero-hours contracts were paid less than average wage.

It revealed that those on zero-hours contracts are paid a national average of £8.83 per hour — a staggering £4 less than the hourly pay of fully-contracted workers.

“The UK has a low pay problem and we are in danger of creating a recovery based on low-paid and insecure employment,” said TUC general secretary Frances O’Grady.

Zero-hours contracts are increasingly common in some of the most physically demanding jobs in Britain including cleaning, catering and social care.

TUC figures show that zero-hours contractors and agency workers are also more likely to earn less than the living wage.

Three-quarters of Londoners on the contracts make less than the capital’s living wage of £8.80 an hour.

“For those at the bottom end of the labour market on zero-hours contracts, the struggle for a fair day’s work for a fair day’s pay has intensified,” Ms O’Grady added.

“The government must tighten the law to prevent abuse of zero-hours contracts which leave staff with minimal job security and no way of knowing whether they’ll be earning from one day to the next.”

The new data has been met with frustration and disgust by those campaigning against the precarious employment scheme.

Food workers’ union BFAWU general secretary Ronnie Draper told the Star: “Zero-hours contracts are a bane of British industry.”

At the University of Manchester canteen workers recently won their claim for permanent contracts after long negotiations between their branch of general union Unison and management.

The university’s communications officer Freyja Peters said she felt that universities had responsibility to set a standard on work and employment conditions.

“There are still issues around low pay and some people on less than the living wage,” she added, “but winning permanent contracts is a small victory towards a larger goal.”

According to left think-tank Class, 80 per cent of Britons are not sharing in the government’s alleged economic recovery.

“Urgent measures need to be introduced in order to tackle the living standards crisis, starting with stable contracts and a living wage,” said Class chairman Steve Hart.