A Hong Kong delegate to China's parliament has said he feels unable to effectively lobby for the territory's interests, and will resign.
Mr Lee was a delegate to China's legislature
Allen Lee said the "political atmosphere (was) getting more and more depressing".
Mr Lee also said he had quit his job as a Hong Kong radio host, complaining of an inability to express himself freely, the third DJ to do so in as many weeks.
Hong Kong enjoys only partial democracy under Chinese rule.
One way in which Hong Kong citizens can hope to influence the mainland's handling of their interests is through delegates to the National People's Congress (NPC) in Beijing.
But Mr Lee said he no longer felt he could do the job properly.
"I don't have the heart to continue with my work as an NPC delegate," Mr Lee said on the commercial radio show Teacup in the Storm.
"I can't achieve the things citizens want me to," he said.
Mr Lee also said on Wednesday that he would resign from his job as host of Teacup in the Storm.
"There are times... I can't say what I want. I have taken up this job for two weeks but I cannot enjoy this show," Mr Lee told reporters.
"This is the most serious situation in terms of polarity on political views and freedom of speech since I took part in the political scene in 1978," he said.
Mr Lee, a popular political commentator, had been filling in for Albert Cheng, who left Hong Kong after saying he had received death threats.
Another radio host, Raymond Wong, temporarily stepped down from his show last week.
Mr Wong said in a statement that he was tired and needed a rest.
But in an interview with Next Magazine, Mr Wong said he had been under pressure from pro-Beijing businessmen to stop being critical of the Chinese Government.
He said it had used coercion and offers of bribery to try to silence him.
Many in Hong Kong are frustrated by what they feel to be political stultification by Beijing.
When the territory was handed over to Chinese rule in 1997, it was promised significant autonomy, including the possibility of free elections by 2007.
But Beijing ruled out that possibility last month, saying that Hong Kong was not ready for it.