Dumped minister to retire from Senate

The Liberal Party expects a Melbourne Cup field of candidates to fill the Senate vacancy caused by the retirement of dumped minister Michael Ronaldson.

Senator Ronaldson would have led the coalition's Senate ticket for Victoria at the 2016 election but announced his retirement on Friday, having been passed over by Malcolm Turnbull in September for a frontbench role.

He will retire after the party has preselected his replacement.

"My decision will allow the party to continue the renewal process and will allow me to pursue opportunities elsewhere," Senator Ronaldson said in a statement.

The former MP for Ballarat spent more than 17 years on the frontbench, serving as minister for veterans affairs and special minister of state in the Abbott government.

Senator Ronaldson insists he maintains a "close friendship" with Mr Turnbull and his wife Lucy.

"I have no doubt Malcolm's time as PM will be that of a nation builder and a driver of national prosperity."

The Victorian Liberals administrative committee is expected to meet before Christmas to discuss the replacement process and open nominations.

The coalition's Senate ticket currently includes the Bridget McKenzie (Nationals) in second spot and the Jane Hume (Liberals) in third position.

It is likely, but not yet formally decided, that whoever fills the casual vacancy in the lead-up to the election will also take the number one spot on the ticket.

Ms Hume, a superannuation policy adviser and former Melbourne Royal Children's Hospital director, is expected to contest the vacancy - having been on the campaign trail for the past eight months.

"Best wishes to my would-have-been ticket mate ... I wish you every happiness with the next stage," she tweeted on Friday.

Other names mentioned include human rights commissioner Tim Wilson, Institute of Public Affairs deputy director James Paterson and indigenous employment manager Sean Armistead.

Hundreds of party members are expected to vote in the preselection early next year.