Cheng, a Hong Kong citizen, worked for the British government for almost two years until he fled after he said he was beaten and tortured by China's secret police.
"A shadow parliament can send a very clear signal to Beijing and the Hong Kong authorities that democracy need not be at the mercy of Beijing," he told Reuters in London. "We want to set up non-official civic groups that surely reflect the views of the Hong Kong people."
He said that while the idea was still at an early stage, such a parliament-in-exile would support the people of Hong Kong and the pro-democracy movement there.After Prime Minister Boris Johnson offered millions of Hong Kong residents the path to British citizenship following China's imposition of a new security law for the territory, hundreds of thousands of people would come to the United Kingdom from the former British colony, Cheng said.