In the Lords, Lord Alton of Liverpool, a crossbencher, and Baroness Kennedy of The Shaws, of Labour, also had sanctions imposed.
Boris Johnson immediately showed his solidarity, saying: “Freedom to speak out in opposition to abuse is fundamental and I stand firmly with them.”
In their letter to Sir Lindsay, seen by The Telegraph, the sanctioned MPs described the measures as “threatening, and an attempt to silence us and our colleagues and undermine the safety of us all”.
They added: “It is unthinkable therefore that parliamentarians should have to suffer this infringement on our liberties whilst the prime representative of the Chinese government in the UK is still apparently free to come to Westminster and to use facilities here as a mouthpiece for his regime.”
Mr Graham, the MP for Gloucester, sought to justify issuing the invitation to Mr Zheng, who took up his post in January, saying: “There was no question of anything being inappropriate. In my view, whatever the circumstances and situation, it is always better to engage than to not engage.”