BEIJING (Reuters) – China said on Monday that “diehard” independence supporters in Taiwan and Hong Kong were seeking to link up to hatch separatist plots, but that they would never succeed.

Dozens of pro-Beijing lawmakers walked out of the Hong Kong legislature last Wednesday to prevent the swearing-in of two pro-independence activists, setting the scene for a new constitutional crisis in the Chinese-controlled city.

Asked about the case the following day, Chiu Chui-Cheng, spokesman for Taiwan’s Mainland Affairs Council, said the two had been directly elected and called on China and Hong Kong to respect the will of the public.

China’s Taiwan Affairs Office said on Monday the “one country, two systems” model for Hong Kong had been fully implemented since the former British colony returned to Chinese rule in 1997, receiving widespread support in Hong Kong and internationally.

“We resolutely oppose the Taiwan authority meddling in and interfering with Hong Kong’s implementation of ‘one country, two systems’ and words and actions that damage Hong Kong’s prosperity and stability,” it said in a statement.

“Diehard Taiwan independence elements on the island and Hong Kong independence elements are colluding with each other, making futile attempts to split the country.

“This will certainly be opposed by compatriots on both sides of the Taiwan Strait and in Hong Kong and cannot succeed.”

Ray Wong of the “localist” group Hong Kong Indigenous also visited Taiwan last week. The topic of independence has long been taboo in Hong Kong.

China considers self-ruled Taiwan a wayward province and has never renounced the use of force to bring the island under its control after defeated Nationalist forces fled there at the end of a civil war with the Communists in 1949.

Relations between China and Taiwan have worsened since the election of Tsai Ing-wen from the pro-independence Democratic Progressive Party as Taiwan president in January.

(Reporting by Ben Blanchard; Additional reporting by J.R. Wu in Taipei)