The Government has insisted it is right to take time to make a final decision on the Hinkley Point nuclear power plant despite Chinese warnings that Britain's relationship with Beijing is at a "critical historical juncture".
China's ambassador in London called for a quick decision on the project, in which his country has a one-third stake, and said he hoped the UK would "keep its door open" to the Asian giant.
Prime Minister Theresa May caused shock when she ordered a last-minute halt to finalising the £18 billion Somerset plant to review the situation.
Suggestions that Mrs May has security concerns over the Chinese state investing in critical infrastructure in the UK appeared to anger Beijing, b ut a Government spokesman has insisted she was right to order the review.
He said: "As we've already made clear, this decision is about a huge infrastructure project and it's right that the new Government carefully considers it.
"We co-operate with China on a broad range of areas from the global economy to international issues and we will continue to seek a strong relationship with China.
"The message that we continue to take to the world is that Britain remains open for business and we are the same outward-looking, globally minded country we have always been."
China's ambassador Liu Xiaoming, writing in the Financial Times, outlined his country's experience in managing nuclear plants, and Britain's energy needs.
He insisted the safety and security of the plant would be ensured by the UK's regulatory authorities and China's record of 30 years of safe operation of nuclear facilities.
He said Chinese companies had invested more in the UK than in Germany, France and Italy combined in the last five years and this was partly down to mutual trust and respect between the two countries.
He said the mutual trust is the foundation for bilateral co-operation.
"Right now, the China-UK relationship is at a crucial historical juncture," he said.
"I hope the UK will keep its door open to China and that the British Government will continue to support Hinkley Point - and come to a decision as soon as possible so that the project can proceed smoothly."
He added that it had not been easy for the two countries to come this far, saying: "As long as both sides cherish what has been achieved and continue to expand and deepen our co-operation across the board, bilateral relations will maintain their strong momentum and work for the well-being of both the Chinese and British people."
Jon Trickett, Labour's shadow business secretary, accused Mrs May of "bungling negotiations" over Hinkley Point.
He said: "I am deeply concerned whether the Prime Minister has the diplomatic skills that are needed to renegotiate Britain's trade relations with the rest of the world.
"This is the person, after all, that chose to appoint a Foreign Secretary with the sensitivity of a clown.
"But any loss of Chinese investment matters all the more because of this Government's continued failure to develop a modern industrial strategy and provide the infrastructure and other investment needed to deliver it.
"Only Labour are prepared to take the decisive action, including a £500 billion investment programme backed up by a National Investment Bank, that is needed to stop our economy collapsing in the wake of Brexit."