LONDON, May 9 (Reuters) - Former British prime minister Liz Truss will visit Taiwan next week and meet senior members of the government, her office said on Tuesday (May 9), as she makes a case for Western democracies to toughen their stance towards China.

Truss, Britain's shortest-serving prime minister, took office last September, but was forced to resign less than two months later after her economic policies sparked market turmoil.

Since then, she has given speeches in Japan and Washington about the need for a tougher stance towards China. She will also deliver a speech during her Taiwan visit on May 17.

"Taiwan is a beacon of freedom and democracy. I'm looking forward to showing solidarity with the Taiwanese people in person in the face of increasingly aggressive behaviour and rhetoric from the regime in Beijing," Truss said in a statement.

Britain has warned against the use of military force against Taiwan by China. China's foreign ministry said in response that the greatest threat to peace in the Taiwan Strait was the "separatist acts of Taiwan independence and the connivance and support of foreign forces".

Truss' tenure as prime minister contributed to bringing relations between Britain and China to a low point, though her successor Rishi Sunak is aiming to engage where possible with China while also raising concerns over areas of disagreement.

Foreign Secretary James Cleverly, who served under Truss and Sunak, said that he "made plain" Britain's views on issues including Taiwan in a meeting with Chinese Vice President Han Zheng last Friday, and he is expected to visit China this year.

Some critics of China in Britain's parliament have condemned both an invitation to Han to attend the coronation of King Charles, and the prospect of Cleverly visiting China.