There’s counting of votes going on at a very senior level in the Liberal Party but it’s got nothing to do with November 24. It’s for a ballot after then: numbers work for a leadership contest. Crikey understands it’s absolutely serious. Particularly in a certain Lower North Shore electorate.

Liberals know it’s possible for them to sneak back in without John Howard. If Howard isn’t there, they reason, the succession plans no longer stand. There are four leading contenders for the leadership – Peter Costello, Alexander Downer, Malcolm Turnbull and Brendan Nelson – and two dark horses, Mal Brough and Julie Bishop.

The line that Costello is the natural successor is just that – a line. Spin. His best chance of becoming Liberal leader was a handover in the past few months. That didn’t happen. Costello didn’t challenge because he knew he wouldn’t win. His chances of being elected as leader of the Liberal Party, either as PM or leader of the opposition, are slim. Costello does not have the support of a majority of his colleagues. Neither he nor his politics are liked by many in the parliamentary party.

Howard has done his absolute best to ensure his number two never leads the party. And if the Liberals lose a significant number of seats, Costello will be blamed almost as much as Howard.

Alexander Downer is the only person who takes his ambitions seriously.

Malcolm Turnbull could well lose his highly marginal seat. Many of his colleagues are nervous at the prospect of a Turnbull leadership, after a vicious whispering campaign about his past business deals.

This leaves Brendan Nelson, despite the perceived negatives so often referred to by his colleagues. The diamond earring disappeared along with the second wife, but there are still many in the Liberal Party who regard him with suspicion thanks to his membership of the ALP.

Nelson has performed poorly in the defence portfolio, but he has also always been available to backbenchers and helped colleagues as a speaker at fundraisers and other functions. Liberal MPs acknowledge he has a sharp mind. All this has helped dilute the negatives. He holds a safe seat, too – safe even if the current polls convert to actual votes.

The dark horses are just that: dark horses. Mal Brough fancies himself a tad more than anyone fancies him.

Julie Bishop would be something new, but political success depends on more than a comfortable speaking style and an ability to give a grab for TV. Indeed, she could look patronising.

This election will be tight for the Liberals, but their twin campaign pillars of economic management and a union scare campaign could still get them over the line, even if John Howard is defeated in Bennelong.

If this is the case, they could end up with a former boss of one of the country’s most powerful unions in charge – one time AMA head Brendan Nelson.