Christian Porter has been dubbed "The Leader of the Canberra Six" in a stinging attack from a long-time Liberal Party donor.

Wealthy businessman Julian Stawell recently called into question the level of advocacy Mr Porter provides for his home state.

Minister for Social Services Christian Porter has been dubbed leader of the 'Canberra Six'. Credit:Alex Ellinghausen

Mr Stawell last month wrote to the CEO of the 500 Club, a group that raises funds for the conservative party, denouncing the ineffective advocacy of the six Liberal cabinet ministers from WA, who he dubbed 'The Canberra Six', and calling for support to be withheld from them.

News of the letter caused a ruckus around the city, with Mr Stawell reporting that the flood of responses he received were "very supportive".