The prime minister has been urged to “go full speed ahead” on HS2 by his former leadership rival.
Jeremy Hunt, who challenged Boris Johnson for the top job, told Sky News’ Sophy Ridge on Sunday programme he had long been “ashamed” of the country’s rail network.
For Britain to be a modern, 21st century nation this needed to be “sorted out”, he said.
The former cabinet minister’s comments came after the PM told Tory northern MPs that a decision on the controversial HS2 rail project will be taken “within days”.
Mr Johnson has already indicated he will press ahead with the scheme, which has been dogged by delays and spiralling costs.
He recently told Sky News’ children’s current affairs programme, FYI, that “in a hole the size of HS2, the only thing to do is keep digging”.
Speaking to Ridge, Mr Hunt said: “I am a strong supporter of HS2 – I would go for HS3, HS4.
“As someone who lived in Japan I have always been ashamed at the state of our railways.
“Nearly anywhere else you go in the world they have decent railways, which have had proper investment.
“If we want to be a modern, 21st century country then it’s time we sorted that out.
“I very much hope we go full speed ahead on that one.”
The first stage of the scheme would link London and Birmingham, while the next phase would connect the high-speed route to Leeds and Manchester.
However, there is a suggestion the second part of the plan could now be subject to a review.
In response the Mayor of Greater Manchester Andy Burnham has suggested a “compromise”, which would see work on HS2 north of Birmingham put on hold to prioritise a new east-west rail link from Liverpool to Hull – the so-called Northern Powerhouse Rail (NPR).
Mr Burnham told Ridge: “Basically, HS2 has been designed as a north-south railway and when you come to the east-west bit, the Northern Powerhouse area, it doesn’t work very well.
“If you ask people in the North which one would they prioritise, most people would say get east-west right.”
He added: “If government ministers are listening, I want to make an offer to them.
“If we can all agree that we now prioritise east-west… then I think that’s something we could get behind because we could look at the prospect of an east-west railway across the north opening in the 2030s and HS2 is only planned to come here in the 2040s.
“So, there is room for a compromise here and maybe it’s about taking the team who are working on HS2 north of Birmingham off that project and putting them on Northern Powerhouse Rail.”
This could later be joined up with HS2 in Birmingham, said Mr Burnham.
Concerns have been raised over the major infrastructure project, which having been allocated £56bn in 2015, could now cost up to £106bn, according to estimates.
Some £8bn has already been spent on the mammoth scheme.
Last month, Whitehall’s spending watchdog said HS2 was over budget and behind schedule because its complexity and risks were under-estimated.
The prime minister has been urged to “go full speed ahead” on HS2 by his former leadership rival. Jeremy Hunt, who challenged Boris Johnson for the top job, told Sky News’ Sophy Ridge on Sunday programme he had long been “ashamed” of the country’s rail network.