The chairman of the HS2 rail project has said he expects to be sacked within days – just months after his appointment.

Sir Terry Morgan told the BBC there was disappointment at Westminster about delays affecting London’s £15bn Crossrail project, which he also chairs.

It follows a report in The Financial Times (FT) that Prime Minister Theresa May is poised to sack Sir Terry, who started work at HS2 in August.

He is expected to leave both jobs within weeks after a series of recent disclosures about problems at both projects raised doubts about his performance, according to the FT.

Sir Terry told Radio 4’s PM: “I did get confirmation late yesterday afternoon that that (the report) was a leak, as far as I’m concerned.

“I’m expecting that to be confirmed more formally in the next few days.”

Asked why he thought he was being forced out, Sir Terry said: “I can only but assume, because I’ve not yet been told, that because HS2 is such a critically important programme and with the sense of disappointment around the performance of Crossrail that it was considered to be too risky for a programme like HS2 to continue in my role as chairman.”

Sir Terry was hailed as “world-class” when he was appointed to the HS2 project by Transport Secretary Chris Grayling.

News of his imminent departure has prompted fears of potential cuts to infrastructure spending from unions and criticism from the Stop HS2 Campaign who branded HS2 as “a mess”.

Stop HS2 campaign manager Joe Rukin said: “The bottom line is that HS2 is a mess, it’s always been a mess, and imagining that this is the fault of a man who has only been in charge for four months is a delusional attempt by politicians to absolve themselves of the reality that it is their lack of scrutiny and objectivity that is responsible for HS2 being a disaster.”

Reacting to the earlier reports, unions warned of cuts to spending on rail projects.

Manuel Cortes, leader of the Transport Salaried Staffs Association, said: “My big fear is that blaming ‘spiralling costs’, is Tory code for more infrastructure cuts to come.

“It was always nuts to have one person responsible for heading up both these enormous infrastructure projects. More so now that both are not on target.”

Sir Terry has been chairman on the Crossrail project since June 2009.

It was announced on August 31 that the capital’s new east-west railway will open in autumn 2019 rather than December this year to complete infrastructure and testing.

The project’s budget was increased from £14.8 billion to £15.4 billion in July due to “cost pressures”. It is being predominantly funded by Transport for London (TfL) and the Government.

In October, it was announced both TfL and the Department for Transport had commissioned an independent review of Crossrail’s governance and a separate review of its finance and commercial position.

Sir Terry told the BBC there had been some “unfortunate comment” about who knew what and when about whether the Crossrail project was running late.

“I’m very confident that Crossrail behaved properly,” he said, claiming he told TfL and Mayor of London Sadiq Khan on July 26 the programme could not be delivered this year.

A mayoral spokesman said: “The mayor considers it a damning indictment of Crossrail governance that the Mayor and TfL had to commission an independent report to tell them the true scale of the delays to the project.

“This is the kind of crucial information that really should have come from the chairman, but didn’t.

“The mayor has been clear that he discussed rising cost and schedule pressures with Crossrail Ltd over the summer, including looking at the implications if these issues weren’t resolved.

“At the meeting at the end of July it was clear that the opening date was at high risk of being missed but it was not until the end of August that the mayor, TfL and the DfT were told that the opening of the central section would definitely be delayed until Autumn 2019 – something the mayor has not hidden his anger and disappointment about.”

A DfT spokesman said the department did not comment on “personnel matters”, but added in a statement: “We can confirm that the Crossrail board took the decision to delay the opening on Wednesday August 29 and informed the Secretary of State of that decision on August 30.”