Hitachi is on the verge of putting its plans for a new nuclear power project on hold, according to Japanese press reports.

Business magazine Nikkei Asian Review has published a story that the board of the Japanese multinational is due to meet next Monday when it will officially decide whether to suspend work on the plant.

Hitachi’s UK nuclear subsidiary Horizon has been working on plans for a 2.9GW plant on the Isle of Anglesey, which is one of a handful of sites designated in the UK government’s national policy statement for a large nuclear power station.

The project for the twin reactor station is the most advanced in planning terms after EDF’s Hinkley Point C, which is currently being constructed.

Suspending work on the plant would deliver a heavy blow to plans to rollout a new fleet of large nuclear reactors coming hot on the heels of Toshiba’s decision last November to pull the plug on its plans for Moorside in Cumbria.

Nikkei has reported that Hitachi has had trouble finding Japanese investors to back the project despite the UK government’s agreement to take a stake last summer.

Sue Ferns, senior deputy general secretary at the science union Prospect, said the reports are “extremely worrying”.

She said: “To lose one major nuclear project is a serious blow, to lose two in six months would set alarm bells ringing about the sincerity of the government’s commitment to new nuclear.

“The Japanese prime minister was in Downing Street only yesterday – did the prime minister even think to raise the issue of nuclear new build or was the only thing on her mind the chance to take advantage of his visit to try to give another futile boost to her Brexit deal? It is fast becoming clear that if it’s not Brexit, then this prime minister and her ministers are unwilling to execute their responsibilities as a government.

“New nuclear is of significant strategic importance for the country, the government must not sleepwalk into an energy security crisis by allowing these projects to fail one by one.”

Rebecca Long-Bailey, Labour’s shadow secretary of state for business and energy, tweeted that she is “very concerned” about the report and their implications for the North Wales economy and jobs.

“I’m also concerned about what this could mean for the UK’s energy security, particularly after the collapse of the Moorside plans in 2018.”

A statement from Hitachi said that while the company is assessing the potential suspension of the Wylfa project, “no formal decision” has been taken.

A spokesperson from the Department for Business, Energy and Industrial Strategy, said:”Negotiations with Hitachi on agreeing a deal that provides value for money for consumers and taxpayers on the Wylfa project are ongoing.”

Commenting on the Wylfa nuclear power project, Energy UK’s chief executive, Lawrence Slade said: “The UK’s ongoing transition to a low carbon energy system will require a balanced generation mix where different technologies each have an important role to play.

“It’s therefore important that low carbon and secure sources – such as nuclear – get the necessary investment to enable them to help supply the country’s energy needs over the coming decades.”