Backed by party allies of former prime minister Tony Abbott, Senator Molan is attempting to pull off a rare win by gathering at least 150,000 "below-the-line" votes - which nominate individual candidates rather than parties - in next month's federal election.

The conservative retired general said he had been "dudded" twice by the Liberal Party by being relegated to unwinnable places on the Coalition Senate ticket in New South Wales - once in 2016 and again in next month's federal election.

Senator Molan says he remains a loyal Liberal but is appealing to voters directly to re-elect him. It is highly unusual for a major party candidate to have a parallel campaign that eschews the party and instead promotes them as an individual, but he hopes to follow in the footsteps of Tasmanian Labor senator Lisa Singh, who in 2016 leapfrogged other party candidates into Parliament due to strong personal support.

While he has vowed not to "trash" his fellow Liberals, Senator Molan says voters deserve the choice of a conservative with a strong national security background.

"I intend to win this ... The Liberal Party needs a variety of views, including people who have extraordinary life experience, particularly in the area of the changes to our strategic environment," Senator Molan said.

"I ran the war in Iraq for a year. That is unique experience."

Asked whether the party could properly voice and pursue national security issues without him in parliament, he said: "No they can't."

Senator Molan has been a significant player on parliamentary committees including the joint committee on intelligence and security, which has scrutinised counter-terrorism, foreign interference and encryption legislation.

Senator Molan insisted he was not breaking any party rules. He is telling supporters to vote below the line on the Senate ballot, but is not telling them to vote for him. But he is also informing supporters that if they "vote above the line, then I'm dead and I'm out of politics".

The Senate ballot paper lets voters choose parties above the line and accept the parties' own preference flow, or choose individual candidates below the line.

Senator Molan was placed behind more moderate Liberal candidates Hollie Hughes and Andrew Bragg on the ticket, infuriating many NSW conservatives. He speculated that he had been placed down the ticket because he helped lead a party reform campaign giving members greater voting rights.

A "Re-elect Jim Molan" campaign has been established by Liberal Party figures in Warringah, including Walter Villatora and John Crawford, who were central to the party reform movement.

Election analyst Antony Green estimated Senator Molan would need at least 150,000 votes to overtake the third Coalition candidate on the ticket, National Perin Davey, and redirect preference flows to himself.

"The chances of that are very slight. I'd say fanciful," Mr Green said.