The long-awaited redevelopment of South Kensington Tube station is finally set to begin after Transport for London signed off the contracts to get work started.

Overcrowding and a lack of disabled access at the station will be tackled by the project, which is expected to cost over £120 million.

Step-free access will be installed for all three Tube lines, the eastbound Circle and District line platform reopened and more space created for the 30 million passengers that use the station every year.

There are two parts to the redevelopment – the opening of a new entrance in Thurloe Street that will enable lifts to be installed to the platforms – and an around-station development that will see 50 homes, of which 35% are expected to be “affordable”.

The upgrades will start in December after TfL announced it had awarded the build contract to Costain.

Work is due to be completed in 2031, which is the 150th anniversary of the nearby Natural History Museum.

Andy Lord, London’s Transport Commissioner, said: "I’m delighted that our plans to transform the internationally important South Kensington station are fully progressing.

“Awarding the contract to Costain means that, working closely with Native Land and Places for London - our wholly-owned property company - we can deliver step-free access here for the first time, as well as provide improved space for businesses.

“It will also see the delivery of new homes, including on-site affordable housing, and radically improve the station for the millions of people who travel through or live in and around South Kensington."

The station is the gateway to world-class London attractions such as the Natural History Museum – the UK’s most popular tourist site in 2025 - the Science Museum, the Royal Albert Hall and the V&A.

However, TfL estimates that more than 500,000 journeys a year are not made to or from South Kensington station because of its accessibility issues.

Planning permission for the scheme was signed off in 2023 and had been included in TfL’s business plan but was unfunded.

It is being part financed with £15m from Places for London – TfL’s in-house developer - £12m from Kensington and Chelsea council and £250,000 from the 1851 Royal Commission.

Kensington and Bayswater MP Joe Powell said: “It is fantastic news that work will be starting this year on a step-free and modern South Kensington Tube Station.

“For years, this project was promised but never delivered. When I was elected two years ago, I made it a top priority.

“After years of delays, I brought together Ministers, TfL, Places for London and local stakeholders to get this project moving and over the line. It's taken a lot of work but I'm pleased residents of South Kensington will finally get the station the area needs.”

Elizabeth Campbell, leader of Kensington and Chelsea Council, said: "We have campaigned for years for a South Kensington station that is better for everyone, and we’ve backed that ambition with a significant financial contribution.

“Full step-free access to every line is essential, and the award of this contract is a major milestone towards delivering the station our residents and visitors deserve.”