China bars visit by Australian MPs

Three Australian MPs due to travel this week to China and Hong Kong for a parliamentary delegation have had their trip cancelled unexpectedly.

Chinese authorities reportedly told Australian diplomats in Beijing a fortnight ago that they didn't want the visit to "go ahead at this time".

There's speculation the reason for the cancellation was because Beijing was offended Australia had joined another 10 countries in signing a letter that questioned China's treatment of human rights lawyers.

That saga pre-dates Chinese disappointment Australia would not ratify a 2007 extradition treaty, a decision that emerged after Chinese Premier Li Keqiang's official visit.

Government backbenchers Craig Kelly and Llew O'Brien and Labor senator Lisa Singh were due to depart on the trip to Hong Kong and China on Wednesday.