Malaysian Prime Minister Mahathir Mohamad on Thursday warned the Philippines against letting in foreigners who could “disturb the political equations” as President Rodrigo Duterte’s Beijing pivot sparks an influx of Chinese workers. At least 200,000 Chinese nationals have flocked to Manila since Duterte’s 2016 election, many of them employed by online gaming firms that cater to Chinese players, a Philippine Senate inquiry was told late last year. This has touched off concern, with some Filipino politicians alleging it drives up property prices, takes away jobs from locals and even affects tax revenues. Mahathir, who has suspended several of his nation’s major projects with China, warned during an official visit to the Philippines against allowing a surge of foreigners. US promises to defend the Philippines in South China Sea “Foreign direct investment should not involve bringing huge numbers of foreigners to live in the country because that might disturb the political equations in the country,” Mahathir told ABS-CBN television in an interview. “If huge numbers of any foreigners (come) to live and stay in the country or to even influence the economy of a country, then you have to do some rethinking as to whether it is good or bad, or the limits that you have to impose on them,” Mahathir said. Mahathir, 93, is in the Philippines for the first time since his shock election victory last year. He will meet with Duterte later on Thursday. The Malaysian leader has taken a cautious approach to relations with China, saying he would discuss “unfair” terms of deals signed by his predecessor, Najib Razak. Duterte’s pursuit of closer ties with China for the Philippines – a traditional ally of the US – has prompted a surge of Chinese worker arrivals. Why Manila both welcomes and worries about Chinese investment Last year legislators said around 200,000 Chinese were working in the country, and vowed to introduce protection for Filipinos. Philippine Finance Secretary Carlos Dominguez had also said he would ensure that foreigners working in the nation’s offshore gaming industry paid taxes. However, Duterte last month said Chinese workers should be allowed to continue staying in the country as Beijing also hosted hundreds of thousands of Filipinos. Most of them are domestic workers in Hong Kong. Duterte has warmly embraced China despite his nation’s long-standing maritime row with Beijing over the South China Sea. Beijing asserts sovereignty over almost all of the resource-rich sea, with competing claims from the Philippines, Malaysia, Brunei, Taiwan and Vietnam. Commenting on the sea dispute on Thursday, Mahathir said there should be no impediment to vessels using the strategic waterway, through which trillions of dollars in global trade pass through each year. “The most important thing is that the South China Sea in particular must be open to navigation,” he said.