People who support Taiwan independence would face life in prison, according to a spokesman for China’s Taiwan Affairs Office.

As tensions between the mainland and the self-ruled island China claims as its own increase, this is the first time China has spelled out real punishment for those perceived to be pro-Taiwan independence.

Taiwan’s Premier Su Tseng-chang, Parliament Speaker You Si-kun, and Foreign Minister Joseph Wu were designated as persons who are “stubbornly pro-Taiwan independence” by the office, which made public for the first time a list of those who fell into this category.

China will enforce punishment on the people on the list, by not letting them enter the mainland and China’s Special Administrative Regions of Hong Kong and Macau, said spokeswoman Zhu Fenglian in a statement on Friday.

The blacklisted people will not be allowed to cooperate with entities or people from the mainland, nor will their companies or entities who fund them be allowed to profit from the mainland, she said.

Taiwanese politicians partially rely on donations from companies to fund their election campaigns. Many Taiwanese companies derive profits from doing business with the mainland. Tens of thousands of Taiwanese currently work in the mainland.

China will also take “any other necessary measures” against these people, Zhu said.

She said the message China wants to send to supporters of Taiwan independence is: “Those who forget their ancestors, betray the motherland and split the country, will never end up well and will be spurned by the people and judged by history.”

Taiwan’s Mainland Affairs Council did not immediately respond to a request for comment.