The man who could replace Boris Johnson has pledged to slash "unaffordable" Tube fares by getting businesses and developers to pay up.

London mayoral candidate Stephen Greenhalgh vowed on Tuesday to cut Tube prices by 3% every year he is in office, if elected, by overhauling Transport for London’s back-office functions, slashing non-operating costs and introducing cost-effective technologies more quickly.

He claims this would save Londoners £905.21 on an annual zones one to three travelcard over four years.

Cutting back office costs was one of the legacies Conservative Mr Greenhalgh left with Hammersmith and Fulham Council where he was leader before becoming Boris’s deputy mayor for policing and crime.

Speaking outside St James’s Park Tube station, he said: “Over the last few years the Mayor took tough decisions for the much-needed investment in London’s public transport. This has created extra capacity and improved services.

“However, we must now bring Tube prices down, especially for those who keep the city running – the nurses, teachers and paramedics. Fares have reached the point where they are unaffordable for many working people.”

If Mr Greenhalgh was voted in an annual zones one to three travelcard in 2021 would be £1,335.02 compared to the forecast £1,697.27 with inflation - £172.98 cheaper than today’s price.

A single cash fare in zone one would be £4.25 instead of £5.40 with inflation, which is 55p cheaper than the current fare.

He told getwestlondon how some people struggle to earn their fare to work in the first hour of their shift and, continuing with the annual fare hikes, “will hamper London’s economic growth for years to come unless tackled”.

Mr Greenhalgh said the capital needs more transport investment but passengers cannot be expected to shoulder the burden, it should come from businesses and developers who directly benefit from new tube lines.

“People don’t believe this can be done,” he added. “But I have a track record of delivering on my pledges of reducing costs for hard-working Londoners while maintaining high-quality public services. The savings we can make from TfL will be ploughed back into keeping fares falling.”

The announcement comes after a YouGov poll found cutting transport fares is Londoners’ top demand of the next mayor.

If voted in as Mayor of London, starting in 2016, the Tube fare cuts would start in January 2017.

He has also pledged to provide more affordable housing, protect neighbourhood policing numbers and ensure every London child has a good school place.