The government is to make the final decision on whether to proceed with the high speed rail link HS2 on Thursday.
Prime Minister Boris Johnson, Chancellor Sajid Javid and Transport Secretary Grant Shapps will meet to come to a final position.
It is not yet clear when the government intends to announce the final decision.
It follows a leaked review of the project suggesting it could cost almost double the £56bn originally expected in 2015.
Phase 1 of the rail line between London and Birmingham is due to open at the end of 2026, with the second phase to Leeds and Manchester scheduled for completion by 2032-33.
It is designed to carry trains capable of travelling at 250mph.
Billions have already been spent on HS2, but Mr Shapps has refused to rule out scrapping it entirely.
The transport secretary revealed last week he had asked for more data before making a “massive decision” on HS2, after a leaked government review found it could cost £106bn.
The unpublished report, which was leaked to the Financial Times, said there was “considerable risk” that estimated costs could rise by another 20%.
The government had previously promised to make a decision on HS2 before the end of 2019.