London's mayor Boris Johnson has written to Chelsea, Arsenal, Tottenham, Fulham and West Ham urging them to pay all of their staff a "living wage".

The Guardian says Johnson took action in response to a survey found Premier League clubs paying cleaners, catering staff and programme sellers at or just above the minimum of £5.52 an hour.

The survey, by Fair Pay Network, found jobs advertised at Manchester United and Liverpool at £5.52, vacancies at Fulham on £6 per hour, Spurs looking for warehouse staff for £5.75 per hour, and similar rates at other Premier League clubs.

In his letter, Johnson said: "Concerns have been raised with me about low-paid workers at London's five Premier League clubs."

He argues, as does Fair Pay Network, that the clubs would benefit if they paid better.

"Staff who are paid at a level that can reasonably sustain them tend to be more productive, loyal and committed," it said. "It would set a superb example for your club to agree to pay your low-paid workers - shop assistants, catering staff and cleaners - the London living wage, and I urge you to do so."