Cory Bernardi is poised to announce a Victorian MP is joining his Australian Conservatives party just days after applying to register the party in Victoria ahead of next year's state election.

Fairfax Media understands the South Australian senator will on Monday reveal the Victorian upper house MP Dr Rachel Carling-Jenkins will defect to the Australian Conservatives. And further defections in Victoria and possibly NSW are anticipated, according to party insiders.

Fairfax Media can reveal Senator Bernardi's party has broken the 10,000 mark for memberships nationally. By contrast, the Victorian division of the Liberal Party is understood to have about 13,000 members and the NSW division about 10,500. Support has fallen since the 2015 leadership change from Tony Abbott to Malcolm Turnbull, but senior sources have scotched internal party claims made by disaffected members that the number in NSW has slipped below 10,000.

Dr Carling-Jenkins represents the Democratic Labour Party (DLP) and her defection will spell the end of the troubled party's representation across the country. It also follows the federal Coalition's successful passage last week of a schools funding formula, which short-changes Catholic schools by up to $3 billion. The DLP's last federal representative John Madigan also defected to set up his own John Madigan's Manufacturing and Farming Party. It flopped when he was booted out of the Senate in the double dissolution election last year and he has since joined the Australian Country Party.