Sir Iain Duncan Smith has branded James Cleverly’s visit to China “project Kowtow”, claiming it “smells of appeasement”.
The former Tory leader said the foreign secretary’s meetings, with Chinese foreign affairs minister Wang Yi and vice president Han Zheng, were “pointless”.
And Sir Iain warned ministers appear more interested in boosting trade than defending human rights and democracy.
He said: “This is just the latest stage of project Kowtow.
“The problem with our position right now is it smells terribly of appeasement. It’s like we want more business, therefore we don’t want to upset the Chinese too much.”
And he told Politico that for the trip to be a success, Mr Cleverly had to tell the Chinese “categorically and publicly their behaviour is unforgivable — the genocide, the torture, the slave labour, Hong Kong’s National Security Law”.
Hitting back, Mr Cleverly said he had raised human rights issues during “every single one” of his meetings with Chinese officials.
Pressed on whether simply raising human rights obligations was enough, amid concerns about abuses in Xinjiang province, Mr Cleverly said: "This will continue to be an area of discussion that I bring up alongside other areas, and I’m not going to change my posture on that.
"And I think the Chinese government understand the UK is consistent in our approach. I am consistent in my approach and I will keep raising these issues with the Chinese government."
But he said Britain is “clear-eyed” that China is not going to change “overnight”.
Mr Cleverly said: “We’re certainly not going to do it in any one individual meeting.
"But it is important that we maintain regular dialogue, regular lines of communication. That is what I am doing, because we do seek to influence, that is what diplomacy is all about.
"We do seek to influence China."
Meeting his British counterpart, Mr Yi told Mr Cleverly that Sino-British relations can "eliminate all unnecessary interference" if both countries "adhere to mutual respect".
"I believe that as long as both sides adhere to mutual respect, equal treatment, view each other's development objectively, and enhance mutual understanding and trust, Sino-British relations will be able to eliminate all unnecessary interference and obstacles," Wang said during the meeting's opening remarks in front of reporters.
Cleverly is the first senior British minister in five years to visit China, a trip aimed at resetting ties between the two countries after years of tension over security, investment and human rights concerns.
Mr Cleverly’s visit is the first by a UK foreign secretary since 2018 and is aimed at resetting relations with Beijing.
If successful, it could pave the way for talks between Rishi Sunak and Mr Xi, with both leaders invited to attend the G20 summit in India in September.
But as well as Sir Iain, Mr Cleverly’s visit has been criticised by China hawks on the Tory benches, who want a tougher line against the state which has sanctioned several British MPs and peers for speaking out about human rights violations.
Alicia Kearns, chair of parliament’s foreign affairs committee, said the trip is “an opportunity to bring to an end two decades of failed deterrence”, but said it “needs to achieve outcomes”.
Ms Kearns said she urged Mr Cleverly to pressure the Chinese on human rights concerns ahead of the trip.
And, ahead of the G20 summit, she said Mr Sunak should "absolutely" meet Chinese leader Xi Jinping if the opportunity arises because that is "how you prevent and deconflict potential issues".
But, speaking to LBC, Ms Kearns warned the Chinese Communist Party is tracking the prime minister’s location using electronic devices in many cars in the UK.
