A former senior government minister has given a tearful final speech to Parliament, warning that Australia's ability to implement policy has been undermined by "the revolving door in Australian politics" in recent years.

Joe Hockey told Parliament on Wednesday that the stability of Prime Minister John Howard's conservative government, which was voted out in 20007 after more than 11 years in power, "has been replaced with rapid and unpredictable changes of government."

Hockey announced last month he was quitting Parliament after Prime Minister Tony Abbott was replaced by Malcolm Turnbull in a shock vote of ruling party lawmakers. Hockey had been treasurer which is regarded as the government's most important portfolio after the prime minister.

Australia has had five prime ministers in five years.