Cory Bernardi is closing down his breakaway Australian Conservatives party two years after he defected from the Liberal Party, telling supporters "we are all disappointed by our Party performance at the last election".

The South Australian Senator also said the Liberals' change from Malcolm Turnbull to Scott Morrison meant his party was "no longer valid" but did not say whether he will quit Parliament or serve out the remaining three years of his term as an independent.

Senator Cory Bernardi has de-registered his Australian Conservatives party. Credit:Andrew Meares

Senator Bernardi famously quit the Liberals in 2017 complaining that the party was heading in a direction that was too left-wing under then-prime minister Malcolm Turnbull.

Inspired in part by the election of Donald Trump as US President in November 2016, he formed his Australian Conservatives party in early 2017 after returning from a stint in New York.