DP World, the parent firm of P&O Ferries, will attend the government’s international investment summit on Monday.

There were reports the company had pulled out of the summit, where it was expected to announce a £1bn investment in the UK, after the transport secretary, Louise Haigh, called for a boycott of P&O.

On Saturday the Department of Business and Trade confirmed DP World will attend.

Earlier, Keir Starmer rebuked Haigh for her comments, in which she described the firm as a “rogue operator”.

Announcing new worker protections, Haigh said on Wednesday that she had boycotted the ferry company and told the Department for Transport not to have any dealings with either it or its owning group.

Shortly after her comments, DP World, the Dubai-based owner of P&O Ferries, put the announcement of a reported £1bn investment in the UK on hold.

“I think we’ll resolve that,” the prime minister told the BBC’s Newscast podcast.

The announcement of plans by DP World to expand its London Gateway port was expected to be a key part of the Labour government’s summit. The event, a showpiece to attract foreign money to the UK, is to be attended by Starmer and the chancellor, Rachel Reeves.

When asked if Haigh had been wrong to describe the company as “cowboys” and encourage a boycott, he added: “Well, look, that’s not the view of the government.”

A Downing Street spokesperson said on Friday after news of DP World’s pause on its investment: “We welcome P&O Ferries’ commitment to comply with our new seafarer’s legislation, which protects against damaging fire-and-rehire practices.”

It said it was continuing to “work closely” with DP World, which also owns Southampton Port.

P&O Ferries, a subsidiary of DP World since 2019, united politicians in anger in 2022 when it fired 800 crew without warning, replacing them with low-paid agency staff working longer hours, in some cases below the minimum wage.

Announcing moves to end fire-and-rehire practices in the employment rights bill for workers this week, Rayner said the actions of P&O Ferries were “outrageous” and “exactly why we’re taking bold action”.

In interviews on Wednesday, Haigh said she had boycotted P&O Ferries and told the Department for Transport to have no dealings with either the ferry firm or its owning group.

Haigh said on Wednesday: “I’ve instructed my department to have absolutely no contact with P&O Ferries or DP World unless it is literally on safety grounds. The department is not to have anything to do with them, and certainly not engaging with them.”

The Labour MP Liam Byrne, the chair of Westminster’s business and trade committee, told BBC Radio 4’s Today programme on Saturday: “I think there’s a bit of a split here between the past and the future. Lou Haigh was absolutely right to say the behaviour of P&O, owned by DP World, in the past has been completely unacceptable.

“The calls for the boycott, let’s not forget, were originally made by Grant Shapps … but now we have got the employment rights bill coming through, I think we are all expecting businesses to play by the rules.”

The Dubai firm owns the port of Southampton as well as London Gateway and was involved in the creation of some of the first of Rishi Sunak’s controversial freeports.

The shadow business and trade secretary, Kevin Hollinrake, said after DP World’s initial decision to pull out of the summit – but before its change of heart – that it was a “body blow for the government”, adding: “Just 100 days in, new investment should be rolling in, not being scared off because of anti-business statements or worries about the impact of Labour’s employment and tax policies.”