(Reuters) -British Foreign Secretary James Cleverly is due to visit China at the end of this month, three sources familiar with the matter said, a long-awaited trip seeking to stabilise a turbulent relationship that has sunk to its lowest point in decades.

Britain's foreign office said it would announce Cleverly's travel plans "in the usual way". The Chinese foreign ministry did not immediately respond to a request for comment.

Cleverly was expected in China towards the end of July, but the trip never materialised as China announced the unexpected replacement of his counterpart Qin Gang with former Chinese foreign minister and veteran diplomat Wang Yi.

Qin went missing for over a month before being replaced on July 25, with the details behind his removal left unclear by the Chinese government. He has not appeared in public since late June.

Cleverly is due to land in Beijing on Aug. 29, one of the sources said. The other two sources said the trip was expected around the end of the month, without specifying dates.

The trip is only expected to last a couple of days and has been "scaled back from the original plan", according to one of the sources.

All three sources requested anonymity due to the sensitivity of the matter.

Cleverly would be the highest-ranking British official to visit China since the pandemic, after relations nosedived over issues including Beijing's crackdown in Hong Kong and its treatment of Uyghur Muslim minorities in Xinjiang.

The UK government has taken a relatively hawkish approach to China, with Prime Minister Rishi Sunak declaring that Beijing poses the "biggest challenge of our age to global security and prosperity" in May.

Sunak is also under increasing pressure from some lawmakers in his ruling Conservative Party who are seeking to harden London's policy on China. The UK is also home to large Hong Kong and Uyghur diaspora communities, whose activists are vocal on China's alleged human rights abuses.

After Beijing lifted COVID restrictions earlier this year, a slew of high-ranking European and U.S. officials visited the country, some with great fanfare. A few senior UK government officials have visited China in recent months, but these trips were relatively low-key in comparison.

(Reporting by Joe Cash, Martin Quin Pollard and Laurie Chen in Beijing; Editing by Robert Birsel, Philippa Fletcher and Hugh Lawson)