Retailers have come under fire after investigations by The Independent revealed that not a single high street retail chain has guaranteed staff the living wage.

Last week National Express became the first transport company to become an accredited UK-wide living-wage employer, joining 1,200 firms in paying the independently set hourly rate of £7.85, or £9.15 in London. The wage is linked to the cost of living and is set with the aim of ensuring a decent minimum standard of living.

Retailers are conspicuous by their absence from the list, with even “ethically” branded chains such as John Lewis and the Co-operative not signed up. Citizens UK, the charity that launched the living wage campaign and set up the Living Wage Foundation, said retailers employed the biggest group of low-paid staff and needed to consider their social responsibilities. Neil Jameson, director of Citizens UK, said: “Not a single high street retailer has accredited as a Living Wage employer, despite posting huge profits, whilst we, the taxpayers, help top up the wages of their low-paid staff through in-work tax credits. It’s a perverse situation when a supermarket worker, despite having a staff discount, can’t afford to shop in the store they work in because of poverty pay, and a full-time member of staff relies on benefits to make ends meet.”

Some smaller retailers have signed up, and Lush, the cosmetics retailer, pays the London living wage in the capital, although outside only guarantees to pay 50p an hour more than the minimum wage.

The call for retailers to do more was backed by the TUC’s general secretary, Frances O’Grady. She said: “Everyone should get a fair day’s pay for an honest day’s work. Far too many retailers have a terrible record not only on low pay, but also on job security, with the growth of zero-hours contracts.” She praised the companies that had signed up for the living wage and said the national minimum wage needed to rise faster as well.

The British Retail Consortium said: “Retailers invest in training their people and that gives them the skills to progress up the career ladder, and out of low pay. For some who lack skills and experience entry-level jobs can be a vital entry point into employment. However, tackling low pay is an issue for all employers and the solution is more complex than upping the minimum hourly rate of pay. Retailing is one of the most meritocratic industries around.”

A spokesman for the John Lewis Partnership said the chain shared “the objective to pay employees fairly”. He added: “Our policy is to pay the market rate for a job and as much above that as can be justified by performance. Our pay ranges typically extend further than those in many of our competitors. On top of that our partners receive a share of our profits as well as other benefits.”