The British government is considering terminating HS2, a flagship new high-speed rail line connecting the capital to northern England, on the outskirts of London as the project's costs soar, the Sun newspaper reported on Friday.

Costs are rocketing as steel, concrete and wages rise, forcing the government to consider stopping the line in west London, instead of Euston, central London, scrapping the need for 7 kilometres of tunnel, the newspaper said.

Travellers would be expected to use the capital's underground network to complete their journeys.

According to the Sun, other options include delaying the extension to Euston or delaying the whole project by two to five years.

Asked about the report, the government did not deny it was considering the west London option, but confirmed its commitment to the track reaching Manchester, in northern England.

"The government remains committed to delivering HS2 to Manchester, as confirmed in the Autumn Statement," a Department for Transport spokesperson said in an emailed statement.

Britain has already scaled back HS2, scrapping a link to the northern city of Leeds, due to the spiralling cost of the project, scheduled for final completion from 2035-2040.

It had faced significant environmental opposition in trying to get HS2 off the ground.

HS2 was expected to cost between 72 billion pounds ($89 billion) and 98 billion pounds at 2019 prices, but since then inflation has soared, with price rises in the construction industry said to stand at 18%.

The 2019 budget also represented a big jump from the 2015 estimate of 56 billion pounds.

Britain was the birthplace of rail travel and has an extensive network dating back to the nineteenth century.

But in the twenty-first century, it has fallen behind European peers like Spain and France which have thousands of kilometres of high speed infrastructure.

In northern England, in particular, the rail network is struggling, hit by a lack of investment and poor management.

The poor state of the transport network is the number one complaint among mayors representing cities in the north of England. On Wednesday they issued a joint statement saying they could no longer accept the current system.

Construction of the first part of HS2, from west London to Birmingham, is already underway. Building the second part from Birmingham to Manchester is slated to begin in 2024. ($1 = 0.8085 pounds) (Reporting by Sarah Young, additional reporting by Andy Bruce; Editing by Kate Holton and Christina Fincher)