Liberal senator Jim Molan has reportedly withdrawn from his scheduled appearance on the ABC’s Q&A after being relegated to an unwinnable position on the New South Wales Senate ticket.

On Saturday Molan – a former army general and one of the architects of the Coalition’s Operation Sovereign Borders policies to deter asylum seekers – was relegated to third in the Liberal preselection, and fourth on the combined Coalition ticket.

The NSW ticket at the 2019 federal election will be led by the Liberal disability advocate Hollie Hughes and former acting federal director of the Liberal party and Business Council of Australia executive Andrew Bragg.

Molan was due to appear on Q&A on Monday alongside Labor’s Doug Cameron and the Greens’ Mehreen Faruqi.

But after the shock preselection loss, the ABC reported that Molan informed the station he “may not come on the show”. “I cannot bring myself to defend my party at the moment,” he reportedly said, before promising to confirm on Sunday. Molan then pulled out, saying again he “would find it hard to defend my party”.

Molan received 141 votes to Hughes’ 199 votes and Bragg’s 157 out of a pool of 520 in the preselection college, which was expanded after a conservative push for more democratic preselections in NSW.

The loss of Molan, a member of the hard right, to Hughes, of the soft right, and Bragg, a Liberal moderate, is likely to inflame tensions in the NSW division.

Relations are already at a low point due to Tony Abbott’s campaign to reduce the factional power of moderates and the ouster of Malcolm Turnbull from the prime ministership by Scott Morrison, who intervened on behalf of Molan.

In December 2017 Molan was elected in a recount triggered by Nationals deputy leader Fiona Nash being ruled ineligible by the high court.

Hughes has had a tortuous path to the top of the Coalition ticket. She beat conservative Liberal Concetta Fierravanti-Wells in a preselection in 2016 but was persuaded by Turnbull to reverse the order to keep peace in the party. Hughes was due to replace Nash but it was ruled her appointment to the administrative appeals tribunal after the 2016 election rendered her ineligible.

Bragg, who led the Libs and Nats for Yes campaign in the marriage law postal survey, received second spot on the ticket after a deal that saw him withdraw from contesting the Liberal candidacy in the Wentworth byelection.

The Nationals hold the third spot on the Coalition ticket, although retiring senator John Williams has suggested the junior partner should run a separate ticket if they are not gifted the second spot to compensate for Nash’s exit.