Former National Party list MP Aaron Gilmore has hinted at a possible tilt at the Christchurch East electorate.
Mr Gilmore resigned from Parliament in May this year amid criticism of his behaviour at a Hanmer Springs hotel and stood for National in Christchurch East in 2011.
Sitting Labour MP Lianne Dalziel last week announced that she would quit Parliament later this year to run for the Christchurch mayoralty against incumbent Bob Parker.
In his online blog, Mr Gilmore said many locals have asked him what he is going to do about the resulting by-election.
He said he has learnt to hold his cards closely and the bottom line is, he does not want to see Labour retain the seat.
Prime Minister John Key said on Monday it is his understanding that if Aaron Gilmore did stand, it would be as an independent.