China "cannot tolerate" accusations that its investment in a British nuclear plant threatens that country's security, state media said Monday, after London surprisingly delayed the giant project.

Beijing has a one-third stake in the plan to build Britain's first nuclear plant for decades at Hinkley Point in southwest England, along with French company EDF, which gave the scheme the go-ahead last week.

The deal had been seen as a cornerstone of a "golden era" of Chinese-British ties pushed by then-prime minister David Cameron and finance minister George Osborne. But the new administration under Theresa May said Friday it would suspend a decision to build the plant until the autumn.

British media said the move was a sign that May took a more sceptical view on ties with China than her predecessor.

Tian Dongdong, a writer with China's official Xinhua news agency, said in a commentary that the delay "adds uncertainties to the 'Golden Era' of China-UK ties", adding that future Chinese investment in Britain could be suspended unless the deal went ahead.

Fears over "China planting back doors" during construction to control critical infrastructure had a "groundlessness and sci-fi scent", the article added.

"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," it stressed.

The project has been criticised for committing British taxpayers to paying above-market rates for electricity for decades to come.

Former British cabinet member Vince Cable, who worked with May when she was home secretary, told media at the weekend that at the time she had been "anxious" about Chinese involvement.

He told Sky News that when Osborne was in charge of the economy Britain had been "uniquely open to Chinese investment".

"Most Western countries, certainly the Americans, took a much more sceptical geopolitical view, and were worried if you get very closely involved with a government with a very different ideology, this potentially gives you serious problems down the road," he said.