The 5.5km project involves the rehabilitation of the disused Watford Junction - Croxley Green branch line and it's connection to the Watford - Rickmansworth branch of the Metropolitan Line to enable trains to run through to Watford Junction. The existing station at Watford will then be closed.

Construction work to re-route LU's Metropolitan line from Croxley Green onto the new alignment is planned to start later this year. Two new stations will be built at Cassiobridge and Watford Vicarage Road, and the line will be served by new S-Stock trains from Bombardier with services every 10 minutes to and from central London during peak times. The first trains are expected to enter service on the line by 2019.

HCC has set aside £230m for the Croxley rail link project, with an additional £34m being provided by the Government.

The project, which is part of a major investment designed to support growth and regeneration in the area, includes creating new links to Watford General Hospital, Croxley Business Park and Cardiff Road Industrial Estate.

Mr David Hughes, LU's Director of Major Programme Sponsorship, says: "Late last year, faced with significant project slippage and cost escalation, the Government asked us to consider stepping in and taking over responsibility for delivery of the scheme. The Mayor has now confirmed that LU should take on the overall responsibility of the project. We have agreed to contribute £16m, which is the approximate cost of the additional train services required to support the link when it opens in 2019."