Transport bosses have said “reassessing” bus routes is vital as a campaign to save the 53 service is launched by councils.

Greenwich, Lewisham and Southwark Councils have started campaigning to encourage commuters to oppose cuts to the 53 bus from Plumstead to Whitehall.

Transport For London has been consulting on what would be the biggest shake-up to the bus timetable in over a decade.

Under the proposals more than 30 routes will be part-axed, including longer services from the south-east to west London, some of which are more than an hour long, including the 53, 171 and 172.

The 53 bus would have part of its route cut and run from Plumstead to County Hall instead of Whitehall.

Officials from all three boroughs have penned a letter to London’s deputy mayor for transport Heidi Alexander and Transport for London’s managing director for surface transport Gareth Powell against the proposed changes.

Commuters would have to get another bus to finish the last stretch of the journey if the 53’s route was chopped down, making the journey longer.

Councillor Denise Scott-McDonald, Greenwich cabinet member for air quality, transport and public realm said: “The opening of Crossrail will mean parts of the borough are more connected than they used to be, but with only one Tube station and a handful of mainline stations, the fact remains that thousands of our residents depend on the bus as their main mode of transport.

“Some of the most deprived parts of the borough, where fewer people own cars, are also the furthest from train stations.”

Transport watchdogs have warned that the cuts will “disproportionately hit” the working class who rely on the services.

TfL predicts many commuters will switch to the Elizabeth line when it opens.

Geoff Hobbs, director of public transport service planning at TfL, said reassessing buses was needed to ensure services were “cost-effective”.

He said: “Buses have a crucial role to play in boosting the number of people using public transport, but they can’t do this without reflecting how London has changed. It is only right that we reassess the network after the significant changes in both London’s infrastructure and how Londoners choose to travel.

“Londoners expect their buses to be where they are needed and run in an efficient and cost-effective manner and that’s what this review is about.”

Hundreds of people have already backed a petition to save the 53 from being shortened, but TfL has pointed out the average bus, which can carry 87 people, has nine people on it towards Griffin Road/Plumstead station and 14 towards Whitehall/Horseguards Avenue in the section of the proposed changes.

Mr Hobbs added: “Our proposals to reorganise the bus network would modernise bus travel in London by matching capacity with demand while reducing bus-on-bus congestion.

“In adapting underused and inefficient services in central London, our plans will help reduce pollution that has such a damaging effect on the health on Londoners.

“The routes 3, 12, 159 and 453 would continue to provide a link for customers who currently use the 53 to travel between County Hall to Whitehall.”

Under the proposals the 171 from Catford bus garage and Brockley to Holborn would be cut to end at Elephant and Castle and the 172 from Brockley Rise could be axed from Clerkenwell to Aldwych.

The TfL consultation closes on November 9 and can be completed online at tfl.gov.uk/consultations