A spokesman for Tang added that his two secretaries are also under quarantine after their family members tested positive for the coronavirus.
Tang was said to be in close contact with all three staff and will therefore not attend the session as a precaution.
The former chief secretary has since taken a rapid test that has come back negative, the spokesperson added.
The annual session of the CPPCC will kick off in the capital on March 4.
Meanwhile, the country’s top law making body – the National People’s Congress Standing Committee – will begin its meeting on the following day on March 5.