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His tenure as an MP has been clouded with questions over his links to Chinese spy agencies and his studies at Chinese military institutions. Yang has always said these associations are above board.
"After careful consideration and talking to my wife and children, I have decided, that after serving three most rewarding terms in the National Party caucus, I will not stand in the 2020 general election," Yang said in a statement this morning.
"Accordingly, I have informed the Party President that I should not be considered by the Regional list ranking committee of the Northern Region in its meeting tomorrow, hence my announcement today."
Yang said he was proud of his contribution to New Zealand-China relations.
"My trips to China with Prime Minister John Key, Ministers and colleagues are some highlights of my political career. I have witnessed the rapid growth of New Zealand's trade with China and I am pleased to have played a role in it."I am proud to be a New Zealander, and a member of the National Party whom I will continue to support into the future."
Yang's association with Chinese institutes fuelled speculation that he was an officer in Chinese military intelligence and a member of the Communist Party.
In response, Yang said he was not a spy but he taught English to spies at a language school run by the Communist Party's People's Liberation Army.