Photo: © 2010 AAP/ALAN PORRITT

During a grilling on ABC TV last night about the mixed messages he has been sending voters this year, Tony Abbott brought his own bona fides into question.

"Politicians are going to be judged on everything they say, but sometimes, in the heat of discussion, you go a little bit further than you would if it was an absolutely calm, considered, prepared, scripted remark.

"Which is one of the reasons why the statements that need to be taken absolutely as gospel truth are those carefully prepared scripted remarks.

"I think we know when we can put absolute weight on what's being said and when it's just the give and take of standard conversation."

John Howard talked of "core" and "non-core" promises soon after becoming prime minister.

But Abbott's admission comes just months out from an election and Labor wasted no time in calling it an embarrassing gaffe that shows he can't be trusted to run the country.

But the coalition is standing by its man, saying the comments show he is a "straight shooter".

Abbott assured voters last night that his stance on WorkChoices is a "very considered position".