Britain should start building the northern part of the proposed high speed rail network earlier than planned, a group of lawmakers said yesterday in the latest report on the project which again concluded it was “essential” for the country.

The project, High Speed 2 (HS2), has divided opinion in Britain because of its £43 billion cost and possible impact on the countryside. The first phase of the scheme between London and Birmingham is due to open in 2026 with the extension to Leeds and Manchester due to start from 2033.

A group of lawmakers drawn from across the three main parties recommended that HS2’s chairman report back on options to speed up the building of the northern part of HS2 so that trains run north of Birmingham “well before” 2033.

Chairman David Higgins, who takes up his role in January, should also look into the possibility of building from the north at the same time as from the south, a change to an earlier plan to build only one way.

The report said the government’s transport department should emphasise that the cost of building the route is £28 billion while the £43 billion total includes trains and contingency costs.

“The project is now commonly regarded as costing £50 billion and rising. This has led to exag-gerated references to HS2 requiring a ‘blank cheque’ from government,” the report said.

The report, the transport committee’s second look at the project in two years, dismissed criticism from opponents who have questioned whether the rail network will generate sufficient benefits to outweigh its rising costs.

“Having reviewed the revised business case for HS2 ... we remain convinced that the project is justified. Bringing high speed rail to the northern cities has the potential to transform the nation’s economic geography,” the report said.