Sadiq Khan has described extending the Croydon Tramlink network to Sutton as a "priority" of his transport policy - but warned commuters “not to hold their breath” waiting for it to get built.

The newly elected Mayor of London today gave his strongest backing yet for the project and praised the existing network for bringing "fantastic" benefits to communities along its route.

But the former Tooting MP, whose predecessor Boris Johnson failed to approve much-discussed extensions from Wimbledon to Sutton or Croydon to Crystal Palace during his two-term tenure as Mayor, cautioned against expecting the "very expensive" scheme to provide a quick-fix to current transport woes.

He said: "I'm in favour of the Croydon to Sutton tram extension. I have seen the benefits made to that part of Croydon, New Addington, where the tram has been fantastic.

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"What I don't want to do is promise it will take 10 years to happen. You'd be holding your breath for 10 years or more, and I don't want you to die."

The proposed extension, which Mr Johnson first expressed support for in 2010 during his first term as Mayor, is estimated to cost about £240m.

Mr Khan gave his tentative backing to the project last year, soon after becoming Labour's candidate for Mayor of London.

After bluntly describing existing transport links as "awful in Sutton and Croydon", the new Mayor there were a number of "short-term" solutions that could be investigated to ease travel between the two boroughs, including the creation of new bus routes and improving the West Croydon-to-Sutton rail link.

He also repeated his intention to bring London's suburban rail routes under the control of Transport for London (TfL) to improve services run by private companies like Southern and Thameslink, whose trains are frequently beset by delays and cancellations.

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In a bizarre sign-off video to mark the end of his eight years as Mayor earlier this month, Mr Johnson assured Londoners the tram extension to Sutton would get built.

The promise came the day before Mr Johnson left City Hall and ceded all responsibility for London's transport infrastructure the incoming Mayor.

TfL's draft 2016/17 budget and business plan, published in March, included a £100m commitment to extend the network from South Wimbledon to Sutton town centre.

But the extension will only go ahead if further funding can be found.

When asked today whether TfL would be opening a formal consultation into the project, a weary Mr Khan said: "This is day nine, I haven't quite sorted that out yet - but it's a priority.

"I want to be realistic to you. It [the tram extension] won't alleviate the problems you're talking about for a long time.

"Trams take a lot of time, you need to think about CPOs [compulsory purchase orders], land... It's very expensive and takes a lot of time to do."

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