P&O owner DP World has put a £1bn expansion of one of Britain’s biggest container hubs on hold after ministers attacked the ferry company’s employment practices.

The Dubai-based business had planned to announce the investment in London Gateway port at a summit convened by Sir Keir Starmer, the Prime Minister, next week.

However, Sultan Ahmed bin Sulayem, the DP World boss, will no longer attend the event after Louise Haigh, the Transport Secretary, and Angela Rayner, the Deputy Prime Minister, described P&O as “unscrupulous” and “exploitative” this week.

This relates to the Government’s efforts to strengthen workers’ rights, which includes vowing to close a “legal loophole” that P&O allegedly exploited when sacking almost 800 workers in 2022.

A DP World spokesman confirmed that the planned investment is under review, as first reported by Bloomberg.

The move marks a blow to Sir Keir’s efforts to reposition the UK as a country that is open for business, as he aims to catalyse investment at a summit next week.

While Ms Rayner and Ms Haigh have long been outspoken in their criticism of P&O, the language used so close to such a critical event calls into question the degree of coordination between them and Downing Street, as well as the competence of government operations.

When asked about the issue on Friday afternoon, the Prime Minister said: “In the last four weeks we have had at least five or six huge investments in the UK, including £24bn today.

“We have got a massive investment summit coming up on Monday where leading investors from across the globe are all coming to the UK. This is very, very good for the country, very, very good for the future of jobs.”

‘Body blow’

However, Kevin Hollinrake, the shadow business secretary, said DP World’s reversal was a damning indictment of the Government’s performance so far.

He said: “On the eve of this much vaunted inward investment event, this is a body blow for the Government and shows that Labour Cabinet ministers have never been in business, don’t understand business and don’t know how to talk to business. They just haven’t got a clue.

“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.”

Liverpool city region mayor Steve Rotheram said he had “very little sympathy” with DP World.

Mr Rotheram told Sky News: “This is the same company that sacked loads of people, so I’ve got very little sympathy with a company that starts moaning about a Government because of the actions that they’ve previously taken against workers in this country.”

The summit in the City of London is due to be attended by hundreds of business chiefs, including representatives of private equity and sovereign wealth funds, and aims to raise billions of pounds in financing.

A government official said they believed the matter was still under discussion with DP World.

Representatives for Ms Haigh and Ms Rayner did not respond to requests for comment.

DP World’s investment in London Gateway would have created two new berths for deep-sea vessels, increasing the port’s capacity by 50pc and adding hundreds of jobs.

This would have aided the expansion of Britain’s trade links, which is viewed as a key component of the Government’s plans to grow the economy and tap global markets following Brexit.

Britain is hoping to strike a free trade deal with the Gulf Cooperation Council, which includes the United Arab Emirates.

The UAE has also pledged to invest £15bn in areas including life sciences and energy, with a state-owned Emirati fund among the frontrunners to help fund the Sizewell C nuclear power station.

London Gateway, located on the north bank of the Thames in Thurrock, Essex, opened its fourth docking berth in July after DP World invested £2.35bn in the site.

The addition of two more berths would have made it the biggest container port in Britain, overtaking Felixstowe, which is owned by Hong Kong billionaire Li Ka-shing’s Hutchison Ports.

DP World, which is ultimately owned by Dubai’s ruling royal family, ranks as the fifth-biggest container port operator worldwide, according to Lloyd’s List.

DP World purchased P&O for £3.3bn in 2006, paying a 70pc premium for a business once described by Margaret Thatcher as “not just a company but the very fabric of the empire”.

A spokesman for DP World declined to comment.