TfL regulatory powers over rail services in and around Greater London. A result of this consultation was agreement by the Secretary of State for Transport, Alistair Darling, to transfer the Silverlink Metro services from DfT to TfL control. Silverlink had two areas of operation: Silverlink County regional services from to , , and ; and Silverlink Metro within the London urban area. When the franchise was split up in 2007, County services were taken over by the London Midland franchise, and the Metro services came under TfL control. TfL decided to let this franchise as a management contract, with TfL taking the revenue risk. Announcements and launch On 20 February 2006, the DfT announced that TfL would take over management of services then provided by Silverlink Metro. Tenders were invited to operate the service under the provisional name of the North London Railway. On 5 September 2006, London Overground branding was announced, and it was confirmed that the extended East London line would be included. On 25 June 2007 a statutory instrument was laid before parliament to exclude the ex-Silverlink metro lines from the franchising process which enabled them to be operated as a concession. On 11 November 2007, TfL took over the North London Railway routes from Silverlink Metro. The following day there was an official launch ceremony at Hampstead Heath station with the Mayor of London, Ken Livingstone; there was also a later media event on the bay platform at Willesden Junction. The launch was accompanied by a marketing campaign entitled "London's new train set", with posters and leaflets carrying an image of model railway packaging containing new Overground trains, tracks and staff. At the launch, TfL undertook to revamp the routes by improving service frequencies and station facilities, staffing all stations, introducing new rolling stock and allowing Oyster pay as you go throughout the network from the outset. After the takeover, all stations were "deep-cleaned", and Silverlink branding removed. Station signage was replaced with Overground-branded signs using TfL's corporate New Johnston typeface. On 15 April 2009 the North London line trains at Stratford moved to new high-level platforms 1 and 2 from low-level platforms 1 and 2, which were needed for the Docklands Light Railway's Stratford International service. The new platforms 1 and 2 are an island platform with step-free access to platform 12 and subway links to platforms 3–11. On 27 September 2009, Imperial Wharf station