The plans announced by Transport Secretary Andrew Adonis envision trains running at up to 250 mph (400 kph) on the 335-mile (540-kilometer) link. The first part of the line, costing up to 17.5 billion pounds (about $26 billion), would run from London to Birmingham, the nation’s second-largest city.

The announcement comes just weeks ahead of a national election, probably in May. The opposition Conservative Party said that it didn’t necessarily accept the proposed route, but endorsed the idea of high-speed trains and said it would start construction two years earlier.