London Underground has said that construction work on the Metropolitan line extension will start next year after a funding deal was agreed.
The funding was agreed between the Department for Transport (DfT), Hertfordshire County Council and Transport for London (TfL). The line extension and two new stations at Cassiobridge and Watford Vicarage Road are expected to be completed by 2020.
London Underground said the scheme would create more than 6,500 permanent jobs and give a £2bn boost to the local economy.
London Underground managing director Nick Brown said: “By 2020 we will have built a 400m viaduct, two completely new stations and numerous new and reconstructed bridges along the route, transforming transport links in Watford. With the funding package complete we’re now turning all our attention to appointing contractors, finalising designs and beginning construction in 2016.”