London, July 25 : China is the biggest long-term threat to Britain, Prime Minister contender Rishi Sunak will say on Monday as he unveils plans to curb the countrys soft power by closing all of its 30 Confucius Institutes, which promote the teaching of Chinese language and culture in the UK. He will take on Liz Truss, his rival in the Conservative leadership race, by effectively accusing the foreign secretary and western leaders of having "turned a blind eye to China's nefarious activity and ambitions" and call for a new Nato-alliance to be set up to counter it, The Guardian reported. In an attempt to move the focus in the Tory leadership race on to national security and international affairs, Sunak is expected to say on Monday that China "is the biggest-long-term threat to Britain and the world's economic and national security", citing the views of the director general of MI5 and head of the FBI, The Guardian reported. "At home, they are stealing our technology and infiltrating our universities," the former Chancellor will say. "And abroad, they are propping up Putin's fascist invasion of Ukraine by buying his oil and attempting to bully their neighbours, including Taiwan." Sunak will also criticise the Chinese government for "saddling developing countries with insurmountable debt and using this to seize their assets or hold a diplomatic gun to their heads", as well as torturing, detaining and indoctrinating their own citizens in Xinjiang and Hong Kong, The Guardian reported. However, the latest front in the battle to replace Boris Johnson immediately saw recriminations from Truss supporters, with the former Conservative party leader Iain Duncan Smith suggesting the announcement was tantamount to hypocrisy, as in the two years Sunak was chancellor the Treasury "pushed hard for an economic deal with China". Smith has been on China's sanctions list since last year, The Guardian reported. Sunak's intervention threatens to further strain relations with Beijing, which have built substantially since the "golden era" only a decade ago. In a report earlier, China's Global Times newspaper said although Beijing did not expect a sea-change in the bilateral relationship under Britain's new leader, it still hoped the two sides could improve ties. It said Sunak had a "pragmatic view of developing balanced ties with China". The current government has taken a harder stance against Xi Jinping's administration over the crackdown on civil liberties in Hong Kong, including a restrictive national security law and electoral reforms in the former British colony. Mutual sanctions have been in place over China's treatment of Uyghurs in the Xinjiang region. /IANS