British Decision on Nuclear Plant Angers China and France

LONDON — The decision of the new British government to postpone a deal on a nuclear power station, to be built by France with major Chinese investment, has shocked both of those countries and is a potentially major step away from the policies of former Prime Minister David Cameron.

The sudden choice of Prime Minister Theresa May not to sign the deal but to take until the autumn for further study, reportedly on security and economic grounds, has angered both Paris, which will be crucial to Britain’s future relations with the European Union after the country’s vote to leave the bloc, and Beijing, which Mr. Cameron had cultivated aggressively for investment and trade ties despite criticism that he was subordinating human rights and geopolitical concerns to commerce.

The menu had already been published for a grand lunch after a signing ceremony last Friday on the Somerset coast, the site of the proposed Hinkley Point C nuclear power station, which is designed to produce 3,200 megawatts with two new French reactors at a cost of at least 18 billion pounds, about $23.7 billion.

The day before, the board of the largely state-owned EDF, the French power utility, voted 10 to 7 to approve Hinkley Point, despite serious concerns about the ability of the company to handle the project and its costs. But late Thursday night, Downing Street said it would not sign the deal the next day as planned.

Travel by French and Chinese officials to Somerset for the party was canceled, and the “hoi sin local lamb skewers” and mackerel ceviche had to be abandoned.

While Downing Street said that Mrs. May had told President François Hollande of France the week before that she would postpone the deal, the board of EDF was taken by surprise. Jean-Bernard Lévy, the company’s chief executive, said he had been unaware of the British hesitation before the board’s vote and found out about it during a newspaper interview.

Mrs. May told Mr. Hollande that her new government wanted to look at the deal again, as any new government would. But since then it has become clear that her main concerns are with the Chinese involvement, and she seemed to be signaling an end to the British willingness to be China’s best Western ally in return for Chinese investment.

Having served as home secretary for six years before becoming prime minister, Mrs. May is security minded and had expressed concerns in cabinet meetings during the Cameron administration about bringing Beijing into such a sensitive project. The project is meant to provide about 7 percent of Britain’s electricity needs.

She was also reported to have been unhappy on security grounds when British Telecom agreed to a deal with the Chinese telecommunications company Huawei.

While China is funding just over a third of the Hinkley Point project, the real advantage for Beijing is that the deal offers China a chance to build and operate a nuclear power plant of its own design at another site in Britain, at Bradwell-on-Sea, in Essex. That reportedly troubles Mrs. May because it could give China control over an important part of Britain’s energy supply.

On Monday, China reacted angrily to suggestions that its investment in the project threatened British security. The official Xinhua news agency published a commentary arguing that the delay “adds uncertainties to the ‘Golden Era’ of China-U.K. ties” and suggesting that further Chinese investment in Britain could be rethought.

“China can wait for a rational British government to make responsible decisions, but cannot tolerate any unwanted accusation against its sincere and benign willingness for win-win cooperation,” the commentary said.

Mr. Cameron and his chancellor of the Exchequer, George Osborne, had made a big pitch for closer economic and foreign-policy ties with China, including a much-criticized state visit last October by President Xi Jinping. The British decision in March 2015 to become the first Western country to join China’s rival to the World Bank, the Asian Infrastructure Investment Bank, shocked the Obama administration.

The Hinkley Point C project is still expected to go ahead at this point, especially given the added British jobs. But Mrs. May could try to alter China’s role. The delay was interpreted as a message to Beijing and Washington that her position toward China is more skeptical than that of Mr. Cameron and Mr. Osborne, who had aspirations of becoming prime minister but whom she fired from government.

On Monday, Helen Bower, a spokeswoman for Mrs. May, said that Britain did not want a break with Beijing. “With the role China has to play on world affairs, on the global economy, on a whole range of international issues, we are going to continue to seek a strong relationship with China,” she said.

As for France, Mr. Hollande has near record disapproval ratings in the polls and faces elections in May. He has pushed for EDF to win the project as a needed lift for the country’s nuclear industry, which has suffered since the disaster at Fukushima in Japan.

This new-generation pressurized water reactor is complex, and the company has experienced construction problems and severe cost overruns as it tries to finish the first ones in Finland and Flamanville, France.

EDF unions, some board members, engineers and senior executives have expressed deep reservations over the financial risks the construction of the reactor entailed for the indebted power company.