The Transport Secretary has backed Crossrail 2 after a “productive meeting” with the Mayor of London last week.

Chris Grayling backed the £30billon project, agreeing there was no doubt London needs new infrastructure to support its growth as the “UK’s economic powerhouse”.

How the project, a proposed rail route from Surrey to central London, will be funded was top of the agenda.

He said: “I am a supporter of Crossrail 2 but given its price tag we have to ensure that we get this right.

“The Mayor and I have agreed to work together on it over the coming months to develop plans that are as strong as possible, so that the public gets an affordable scheme that is fair to the UK taxpayer.”

After reaching a “successful outcome” on funding plans, a public consultation will be launched.

A DfT spokesman said London needed to pay half of the upfront construction costs and that the government had not committed any public funding yet.

Tooting MP Dr Rosena Allin-Khan said a “thorough plan which picks Tooting Broadway over Balham, protects Tooting Market, keeps construction to a minimum and guarantees genuinely affordable homes” must be put before the community.

The route could begin in Shepperton, Chessington South or Epsom in the southwest and head towards Wimbledon, Tooting Broadway and Clapham Junction before crossing the river.

Labour Councillor for Balham and Tooting Bec, Fleur Anderson, said: “Everyone who squeezes into the tube at rush hour welcomes this positive move towards Crossrail 2. Roll on 2030.

“It should come to Tooting Broadway where more transport links are needed so much more than Balham.”

Conservative Cllr for Balham, Paul Ellis, said he was “delighted” and agreed Tooting was the “most sensible location” and “supported by everyone”.

It is not confirmed whether Crossrail 2 will go through Balham or Tooting, leaving the fate of 100-year-old Tooting Market unknown.

Although Transport for London denied this, market manager Roi Mengelgrein said he learned in November that the majority of the space would be subject to a compulsory purchase order if the rail route comes to the area.

Michèle Dix, TfL's Managing Director for Crossrail 2, said TfL had “not confirmed” the “space that might be needed in the market”.

Mr Mengelgrein said: “We are delighted for Sadiq and Chris to be agreeing on a way forward with CR2.

“However, that still does not confirm whether the market will be compulsory purchased or not.

“We need clarification and we need it now.”

Long-time backer of Tooting, deputy council leader Jonathan Cook has called on the Mayor for assurances Tooting Market will be protected from the construction process.

He said: “This Tube line can be delivered without devastating Tooting Market and we want to ensure that all town centre businesses and residents will be listened to and protected.

“It is vital that the existing community is supported through this process so they can take full advantage of the regeneration to come.”

London Mayor Sadiq Khan said he and Mr Grayling would “continue to work together” to get the maximum benefits for the region.