Former defence minister Kevin Andrews has gone on the attack in his safe Victorian seat of Menzies.
Mr Andrews was spotted on Wednesday with a hammer standing near a fence on which one of his campaign signs had been put over the top of that of independent candidate Stephen Mayne.
The conservative Liberal MP, who was dumped from the ministry when Malcolm Turnbull seized the leadership from Tony Abbott in September, was wearing a moon boot as he is nursing a calf injury.
"He is clearly panicking," Mr Mayne said of his competitor.
"This is not what you'd expect a former defence minister to be doing."
Mr Mayne, an award-winning journalist and shareholder activist, told AAP another of his corflutes had been spray-painted over and up to 20 had gone missing in night raids.
Mr Andrews retained the seat in 2013 with a 59 per cent primary vote, having held it since 1991.
He has been turning up daily at a pre-poll centre in East Doncaster.
Mr Mayne's signs describe Mr Andrews as a "Fake Liberal".
"I'm running as the Turnbull candidate - he is running as the Abbott candidate," Mr Mayne said.