Malcolm Turnbull is yet to throw his support behind Wentworth Liberal candidate Dave Sharma, days before a crucial by-election.

Former prime minister John Howard has launched a last-minute bid to save the seat, which he says could be lost if disgruntled Liberal supporters launch a “protest vote”.

It was Mr Turnbull’s decision to quit politics in August that sparked the by-election.

If the Liberals don’t win the seat of Wentworth on Saturday, the Morrison Government will lose its one-seat majority.

But two days out from the by-election, Mr Turnbull hasn’t publically backed Mr Sharma despite requests from Liberal heavyweights.

“You and I have been saying, ‘Where’s Malcolm?'” Andrew Bolt tells Chris Smith.

“He’s been sulking away in New York, refusing to lift a finger to intervene in the desperate Liberal campaign to retain his seat of Wentworth.

“He didn’t have to quit but he did and he set the government a really dangerous test.

“Finally, I bring news. Malcolm Turnbull has intervened in the election, finally, by liking a tweet from a campaign worker in the campaign of Dr Kerryn Phelps, the independent.”

Andrew says this was a “real low act”.

Back handing out policy info & how-to-vote cards for #KerrynPhelps at #WaverleyOval pre-polling station. No longer wondering Where’s Malcolm? Just hoping for strong independent win on Saturday. 🤞#auspol #wentworthvotes #wentworthbyelection @drkerrynphelps @kerrynwentworth pic.twitter.com/83T4yJ2xl0

— Robert Fairhead 📚🤔 (@tallandtrue) October 17, 2018

The ‘like’ has since been removed.

Listener Margaret says she’s “disgusted” by Malcolm Turnbull’s behaviour.

“I want to thank Turnbull for what he’s doing because he’s showed us in Australia why he had to go.

“He’s not a Liberal. No Liberal would have done what he’s done today.”

Click PLAY below to hear the full segment with Andrew Bolt