Fresh doubts have been raised about the future of Wylfa Newydd.
It follows reports that Hitachi is considering whether to scrap the £12 billion plans for a new nuclear power plant.
Ahead of a board meeting on Tuesday, Japanese commercial broadcaster TV Asahi reported that concerns over a predicted rise in construction costs could lead to developers Horizon – a Hitachi subsidary – pulling out altogether by next March.
On the Tokyo stock market, the report led to Hitachi’s shares going up by 2.9%, before ending the trading day up 1%.
Hitachi said it would make no comment on any rumours or speculation surrounding Wylfa Newydd. But last week, chairman Hiroaki Nakanishi warned that the company was facing an ”extremely severe situation” because it wasn’t attracting enough investors to put money into the project.
Talks are continuing between Hitachi and the UK and Japanese governments on whether to directly invest in the project – and according to some sources, the speculation from Japanese media may actually form part of Hitachi’s negotiation strategy for a better deal.
If it goes ahead, work on the new nuclear power station could begin by 2020. But developers Horizon also need to gain full planning permission.
A six-month planning inquiry into whether to grant a Development Consent Order for the project is continuing.