Britain is at risk of becoming "an accomplice to the Chinese dictatorship" a key civil rights activist has said, as President Xi begins his four-day state visit to the UK this week.

Chen Guangcheng, 43, is famous for having legally advocated on behalf of vulnerable groups in China including women, disabled people and the poor. Blind from an early age, he was nominated for a Nobel Peace Prize in 2010 for his work defending victims of religious and political persecution, as well as exposing the issue of forced abortions in China as a result of its one-child policy.

In London to coincide with Chinese President Xi Jinping's visit, Chen told Christian Today that he is disappointed with the lavish welcome Xi received. The president was met with a 41-gun salute in Green Park, and over 1,000 troops took part in a welcome parade. Xi also accompanied the Queen in a royal carriage to Buckingham Palace, where he and his wife, Peng Liyuan, are staying while in the UK.

Campaign groups say Britain is choosing to overlook China's poor human rights record in order to strengthen diplomatic and economic ties – ministers are expecting more than £30bn of trade and investment deals to be secured over the next few days.

"I think the red carpet is not really welcoming Xi Jinping, it's welcoming the money he's bringing," Chen said through an interpreter.

"This is not a real deepening of the relationship between the Chinese people and British citizens. It's really just the strengthening of the relationships between the Chinese Communist regime and the British government."

He accused David Cameron of "kowtowing", to Xi's party, and warned that the UK will "harvest serious consequences" in the future if it aligns itself with China too closely. "My message to David Cameron is that our own experience already told us that the regime is not even taking seriously the care of its own citizens," he said. "How do you expect Xi to honour his pledges or whatever he says?

"We don't want to see Western democracies becoming accomplices with the Chinese dictators. We want them to be standing with the Chinese citizens; the freedom fighters."

Chen is something of a hero among human rights activists. He spent four years in Chinese jail for his advocacy work, and upon his release in 2010 was placed under house arrest. Though legally a free man, he was under constant supervision, and visitors were forbidden. Actor Christian Bale was among those who attempted to visit Chen in his home, only to be violently prevented by security forces.

Miraculously, Chen managed to escape in April 2012 by climbing the wall around his house in Shandong province in the middle of the night, eventually seeking refuge at the US Embassy in Beijing some 400km north. He now lives in America with his wife and two children.

He expressed some hope today that the human rights abuses in China will improve. "The Chinese citizens are waking up," he said. "What we have done has shown the Chinese people that even a blind man who cannot see anything can make a change. How about those of us who can see?"

Religious freedom in China, however, remains under threat. "There is very serious religious persecution," Chen said. Up to 1,700 churches have been demolished or had their crosses removed in Zhejiang province alone as part of a three-year 'Three Rectifications and One Demolition' campaign, supposedly with the aim of exposing and removing "illegal structures" in the region. However, it is widely seen as a move to combat the increasing influence of Christianity in the country, which is experiencing unprecedented growth.

"I think really, the large scale public demolitions of church crosses is a public declaration of war to the international religious community," Chen said, likening the Communist Party's aversion to Christianity to the Taliban in Afghanistan.

Bob Fu, founder and president of advocacy organisation China Aid, also drew parallels between China and other hardline regimes. Xi's arrival in London yesterday reminded him of the way in which crowds once welcomed German dictator Adolf Hitler, he told Christian Today, and said it revealed the short-sightedness of Cameron's government.

By dealing extensively with Xi, the UK is at risk of sacrificing the values of freedom and basic human rights for all that it claims to stand for, Fu added.

Under President Xi, Fu said that human rights have deteriorated rapidly; with more activists and lawyers arrested in the past two years than in the previous two decades combined. In the past three months alone, up to 3,000 have been targeted.

"That should be really alarming to the international community, which is why it feels so regrettable to see David Cameron roll out such a welcome to a Chinese Communist dictator," he said. Xi sees himself as the most authentic successor to the CPC's first Chairman, Mao Zedong – under who's rule millions perished, Fu added.

"I don't expect that human rights and religious freedom will get better under Xi," he said, and it's vital that the UK government stand up to and call out the abuses. He specifically condemned Chancellor George Osbourne's failure to mention "a single word on human rights" during his recent trip there.

"Where is the backbone of David Cameron's government when all of the actions of the Chinese government are in absolute violation of the 1984 UK-China declaration?" Fu asked.

"Why are they keeping silent? What are they afraid of? I think it's very sad that this kind of appeasement policy will give the green light [for China] to do whatever it wants. We need to remind politicians that they should choose to stand with the people, on the right side of history."