Extending the Northern Line to Clapham Junction would be a "fantastic step forwards", a council leader has said. Wandsworth Council is set to investigate whether the extension makes sense, and draw up wider plans to overhaul the busy station.

The masterplan for Clapham Junction and surrounding areas, including the Winstanley and York Road estate, would aim to bring new homes, offices and shops to the area. The council said it is "ambitious for the future of Wandsworth".

Nine Elms and Battersea Power Station opened as the newest stations on the Northern Line in 2021. Labour council leader Simon Hogg tweeted on February 1 that "extending the Northern Line to Clapham Junction station would be a fantastic step forwards".

The council's transport committee unanimously green-lit proposals to draw up the masterplan and carry out early investigations into the extension on Wednesday, February 1. The executive will make the final decision on February 13.

Conservative councillor John Locker said: "The overhaul of Clapham Junction as a station and of course the extension of the Northern Line, which I'm really pleased to see because it's something that we always advocated… I think we consciously made sure that when it was being extended to Battersea Power Station that it was designed in such a way that it would be able to be extended straight into Clapham Junction – but that's going to take a heck of a lot of funding." 

David Tidley, transport strategy team manager, said the investigation would look at issues including whether it is possible to build a railway between Battersea Power Station and Clapham Junction and that he can't "immediately think of why there would be any overwhelming engineering reason why that couldn't happen" – while looking more at funding would come later if investigations moved ahead. 

He said the initial probe would consider "how many people would use it, how many new people would be attracted to it, where would they come from, would they simply take passengers off other forms of public transport and therefore there might be a net reduction in use of other services and income" – as well as how it would work if Crossrail 2 is opened. 

He added: "This is really more about is the scheme a non-brainer or are there some showstoppers that we ought to know about at this stage." 

About the council report into the extension, Conservative councillor Daniel Hamilton said "as good as it is in relation to the Northern Line extension to Clapham Junction, I think [it] already has created some fairly unrealistic expectations in terms of public opinion, public expectations in the borough".

But Labour councillor Sara Apps said: "I would like to commend the council for having the vision to set this forward. I think you have to put the Northern Line on the map to get it on the map and we are starting that process today and I look forward to seeing it delivered." 

The report says: "A pre-feasibility study would help identify if an extension of the Northern Line is likely to be a good or best option for serving the local and wider areas and would provide a useful assessment to assist the council in promoting the scheme to third parties and raising its public profile."

A further report says the masterplan would steer development in the area and aim to "create an enhanced urban heart to an open, better integrated and connected neighbourhood, including the existing and regenerated Winstanley/York Road estate, with an improved station and public transport interchange, new affordable and market housing, and jobs alongside the necessary social and other infrastructure to support community cohesion and inclusive growth".

The report adds the station "presents long-standing challenges of congestion, severance and accessibility" and suffered from overcrowding at peak times before the Covid pandemic, with passenger numbers now increasing again. It says upgrades are "essential to increase capacity, meet safety requirements and improve passengers' public transport experience".

Councillors also called for other improvements to the area at the meeting – including alternatives to the Falcon Road tunnel and making Lavender Hill more accessible.

Network Rail began a makeover of the station in 2022 to slash congestion, including remodelling the Brighton Yard entrance, revamping lifts, building new shops and installing new toilets. The works are set to be completed in spring.

Clare Fraser, cabinet member for transport, said: "We are ambitious for the future of Wandsworth, which includes increasing prosperity and opportunity and delivering a fairer, more compassionate and more sustainable borough. Our proposed Clapham Junction Urban Heart masterplan builds on those ambitions to utilise the many strengths of Clapham Junction to deliver new jobs, growth and new affordable housing.

"Our aim is to work with partners like the Mayor of London, Network Rail and Transport for London to invest in and revitalise the mainline station, and as part of that work we are exploring extending the Northern Line to Clapham Junction. This would be a fantastic step forwards for Wandsworth residents."