Mr Gilmore, who stood unsuccessfully for the seat in 2008 and 2011, said on his blog Mighty Rocket that the public had been asking him what he was going to do.
"The answer to that is simple. The by-election is not likely til after Show Week. So good things come to those who wait," he said on his blog.
Mr Gilmore said he was "hounded out of public office" and had "learnt to hold my cards very closely. Bottomline, I do not want to see Labour hold onto the seat as I do not think this is the best thing for the people".
When asked at today's post-Cabinet conference for a response on any return of Mr Gilmore, Prime Minister John Key said "yea" and cleared his throat.
Asked to expand on his initial response, he said: "Well I'll leave you to interpret it. I don't think it's likely he'll win."
Mr Key ruled out any return of Mr Gilmore to National's caucus, but said he believed that if Mr Gilmore were to stand it would be as an independent.
When APNZ asked Mr Gilmore if he planned to stand, he refused to answer. "I'm not saying anything. The media are all liars.
"You all nearly killed my mother," he said.
Mr Gilmore argued in his blog post that the Christchurch East seat was not a safe seat for Labour, after a loss of 12,000 voters since the earthquakes and new housing developments.
He said the population shift meant many people were now in Parklands instead of Aranui.
National won 13,252 party votes in the seat in 2011, compared to 9100 for Labour.
Lianne Dalziel won the seat by a 5334 majority in 2011.
Mr Gilmore hoped Labour would chose someone young and local to win the seat.
Ngai Tahu manager James Caygill and sitting list MP Clayton Cosgrove are seen as key runners for Labour.
Mr Caygill told media yesterday he would seek the nomination.
Mr Gilmore resigned as an MP last month after he verbally abused a waiter at a Hanmer Springs hotel for refusing to serve his dining party more wine.
- Kate Shuttleworth of APNZ
