Chinese investment in the UK's nuclear power industry could pose a threat to the UK's national security, experts have warned ahead of a state visit by the Asian superpower's leader.
The UK is rolling out the red carpet for president Xi Jinping, who will stay as the Queen's guest at Buckingham Palace next week.
Mr Xi and his wife Peng Liyuan will spend three days in London where the Chinese leader will hold talks with Prime Minister David Cameron at Downing Street before joining him for dinner at Chequers.
A fourth and final day will be spent carrying out engagements in Manchester.
In a sign of the growing trade and investment links between the UK and Beijing, an announcement on Chinese backing for the new nuclear power station being built by EDF at Hinkley Point, Somerset, could be made during Mr Xi's visit.
Chancellor George Osborne has already offered a £2 billion Government guarantee to help secure funding for the Hinkley Point C plant and indicated that the next step may be a Chinese-designed, Chinese-built nuclear plant at Bradwell in Essex.
But The Times reported senior military and intelligence figures have warned ministers that plans to allow China to take a stake in sensitive national infrastructure could pose a security risk.
One of the Chinese backers is the China National Nuclear Corporation, a state-owned body which helped to develop the country's nuclear weapons.
"There is a big division between the money men and the security side," a security source told the newspaper. "The Treasury is in the lead and it isn't listening to anyone - they see China as an opportunity, but we see the threat."
Downing Street insisted the Government would not pursue the deal if it was thought to pose a security risk.
"This is potentially a very strong and good deal but ultimately we will ensure that all safety and security aspects are continually reviewed and taken into account at all times," a Number 10 spokesman said.
"We wouldn't be pursing this course of action if we felt there was a risk to security."
Energy Secretary Amber Rudd said: "The Chinese can come and engage with us, but is is our regulations, our high standards that they will have to live up to."
The state visit is likely to be used by protesters to shine a spotlight on China's human rights record and security will be tight as the Chinese leader and members of the Royal Family carry out engagements.
Protesters from the Free Tibet group, as well as those supporting persecuted Uighur Muslims, are planning demonstrations, while Labour leader Jeremy Corbyn is expected to raise concerns over human rights abuses when he calls on the president at the palace.
Security will be tight during Mr Xi's visit as the Chinese leader and members of the Royal Family carry out their engagements.
Last month, the head of MI5 warned that the level of terrorist plotting against Britain was at its highest for nearly four decades.
Mr Xi arrives on Monday, but the state visit officially begins on Tuesday when he receives a ceremonial welcome in central London.
He will be greeted at the Mandarin Oriental Hotel by the Prince of Wales and the Duchess of Cornwall and escorted to Horse Guards Parade before taking a state carriage procession back to Buckingham Palace for lunch.
Charles will miss the state banquet hosted by the Queen in the evening, but will hold one-to-one talks with Mr Xi when he invites him to tea at Clarence House in the afternoon.
The Prince, who is a supporter of the Dalai Lama, has had a difficult relationship with China's leadership in the past, but a royal source stressed that he was heavily involved in this visit and using the opportunity to have a personal dialogue with Mr Xi rather than meeting him with a cast of thousands.
While Charles will not be at the banquet, the Duke and the Duchess of Cambridge are widely anticipated to be attending the evening affair - the couple's first state banquet in the UK - but the guest list is yet to be officially confirmed.
Mr Corbyn will also be among the guests - although aides have refused to confirm whether he will follow the recommended dress code of white tie and tails.
William will call on the president at the palace ahead of the banquet and the Duke and Duchess will join Mr Xi at a UK Creative Industries event in London on Wednesday.
The Duke visited Beijing earlier this year and is set to record a speech on illegal wildlife trade on the eve of the visit which will be later broadcast on Chinese television.
Officials are particularly keen to ensure the trip goes well, with Mr Cameron and Mr Osborne keen to deepen Britain's ties with the world's second-largest economy.
UK-China relations were briefly thrust into the deep-freeze after Mr Cameron's meeting with the Dalai Lama in 2012 prompted outrage in Beijing.
But Mr Osborne has just returned from a charm offensive in China designed to open up new markets for British companies and secure billions of pounds of investment in projects such as HS2 and the so-called Northern Powerhouse.
Lord Mandelson, the new president of the Great Britain-China Centre, insisted the planned investment was not a "trojan horse".
The former Labour cabinet minister said: "Vigilance is justified but security concerns should not be allowed to drive knee-jerk responses to Chinese investment?.
"This investment is not a Chinese trojan horse, penetrating our defences so as to cause disruption. China knows that should it ever use critical infrastructure investment as a cover for inappropriate activity, Chinese investment will not be allowed to see the light of day again, anywhere in the West.
"So they cannot afford to mess around."