In his first three months as prime minister, Sir Keir Starmer has acknowledged that he has had "choppy days."

The prime minister described his new position as "much tougher than anything I've done before, but much better" in an interview with the BBC Newscast.

Referring to the government's early successes as "the biggest shake up of workers rights in a generation" and resolving pay disputes in the health service, he acknowledged that there had been "bumps and side winds, which, you know, I'd prefer we hadn't bumped into and been pushed by."

When asked what he meant, Starmer responded, "things about donations, staffing issues, that kind of thing."

Last weekend his former chief of staff Sue Gray resigned, after weeks of infighting and rows in Starmer’s senior team.

The PM also repaid thousands of pounds he had received in gifts and hospitality after a row lasting weeks about ministers accepting freebies.

But he added: “When I look at what it was I wanted to achieve in the first 100 days and ask myself, have we done what I wanted us to do, what I planned for us to do, the answer is yes.”

He also hinted at a focus on dealing with NHS waiting lists in England in the Budget later this month.

The Conservative Party said: "From defence to pensions, health to education, Labour have let the country down. The next 100 days are set to be even worse."

Speaking to Newscast to mark his first 100 days in office, Starmer publicly rebuked his Transport Secretary Louise Haigh after she described P&O ferries as “cowboy operators” who she has been boycotting in recent years.

Her criticism of the firm stems from its decision in 2022 to sack 800 seafarers and replace them with cheaper workers. It insisted this was necessary for the ferry operator's survival.

Crucially, Haigh also encouraged others to boycott the firm.

It has been reported by Bloomberg that P&O’s parent company, DP World, postponed announcing a major £1bn port investment in the UK in the light of the remarks.

The company's boss is now thought to no longer be attending an investment summit organised by the government next week - where DP World was expected to unveil the expansion.

The BBC understands discussions between the government and the company are ongoing to try to tempt them to turn up on Monday, with the investment hanging in the balance.

When asked if his transport secretary had been wrong to describe the company as cowboys and suggest a boycott, Starmer said: "Well, look, that's not the view of the government."

It is the first time since Labour came to power that the prime minister has publicly taken issue with remarks from one of his cabinet ministers.

Senior figures were incensed at the suggestion from a senior minister of a boycott – at just the point they are trying to claim they lead a “pro business” government.

Starmer added that he believed the investment summit was evidence of a growing confidence from companies in the UK’s economy.

Asked what might seal the deal for firms in choosing the UK, he said: “I think what will convince them is that we have listened to what they've told us about economic stability.”

He claimed they had been put off in recent years because of “a lack of confidence in the last government".

"Prime ministers were changing frequently. Ministers were changing frequently. There was no clarity of strategy and those sticking to the strategy."

Starmer also reflected on how his life has changed since he moved into No10.

“We're living in a flat in Downing Street above the shop, and that's not very normal. Everybody who wants to come and see you has to come through an armed guard. This is odd.”

He said the job meant he saw less of his family than he would like and that he “didn't have kids to sort of visit them when they're grown up and find out what they're really like. I had kids because I want to be with them, enjoy their company.”

Starmer said, though, there had been one unforeseen benefit of living in Downing Street: “When our children come back from school about four-ish, they pop down to my office in Downing Street, and if I'm around, I can see them for 5 or 10 minutes.

"That would never have happened before because they would have gone back home in Kentish Town, I'd have been in Westminster or wherever.”