Punters believe it is more likely than not Prime Minister Tony Abbott will face a leadership ballot before the next election.

Online bookmaker sportsbet.com.au says Mr Abbott is now odds on to face a challenge this term, with odds that his leadership will be tested shortening from $4 on December 2 to $1.65 on January 29. The odds of no challenge to Mr Abbott's leadership before the election have drifted from $1.20 in December to $2.15.

Sportsbet.com.au spokesman Will Byrne said Mr Abbott's decision to award a knighthood to Prince Philip on Australia Day appeared to be a "tipping point" for punters.