High Speed 2 (HS2) is a planned high-speed railway in the United Kingdom linking London, Birmingham, Leeds and Manchester. It would be the second high-speed rail line in Britain, the first being the High Speed 1 line connecting London to the Channel Tunnel. The line is proposed to be built in a "Y" configuration in two phases, with construction work on the first phase set to begin in 2017, reach Birmingham by 2026, Crewe by 2027 and be completed in 2033.