Deputy Prime Minister Wayne Swan has expressed frustration at the continuing line of questioning over the latest leak to hit the Gillard Government.

Channel Nine on Tuesday night aired claims that Julia Gillard had lobbied in Cabinet against the Government's paid parental leave scheme and had reservations over the rise in the age pension.

Ms Gillard angrily defended her position on the policies on Wednesday, saying she would always question whether policies were affordable.

"Of course I wanted to see a pension increase - of course I wanted to see paid parental leave," she said.

"I looked at them from every angle. I held them up to the light. I examined every possibility. I asked every question because I wanted to satisfy myself they were affordable."

Speculation over the source of the leak overshadowed the latest inflation figures, which were well within the Reserve Bank's target range and good news for the Government which is now likely to dodge an interest rate hike during the election campaign.

In a heated interview on ABC TV's 7.30 Report, Mr Swan acknowledged people had a right to be interested in the claims but refused to buy into speculation former prime minister Kevin Rudd was the source of the leak.

"I'm not surprised there's some focus on Kevin during the campaign. Leadership changes are difficult for political parties," he said.

"In any campaign there's always going to be a focus about things like this. It's only natural. I don't think there's anything anyone can do about that focus.

"We can't control leaks and I certainly can't predict where they're coming from."

The Treasurer also denied there was a pattern of "tit-for-tat" to the leaks and said they were not a sign of instability within the Government.

"I think that's absurd.... I don't engage in the conspiracy theorists' practice. Usually these things are far more complex than they appear," he said.

Mr Swan tried to move the interview back on to the Government's record several times and refused to answer the question of when he last spoke to Mr Rudd.

"I'm not going into the nature of the discussions I've had with him or the timing of the discussions I've had with him," he said.

"It simply feeds the sort of [speculation] stories you're talking about.

"What I want to do is talk about the issues, the important issues that your viewers want to know about in this campaign."

Quizzed on the lack of Labor Party branding on Mr Rudd's campaign material, the Treasurer said for anyone to read anything into the material was "absurd".

"This wouldn't have been the first time Kevin Rudd has had posters without Labor on them... I in past times have not had Labor on my signs either. There's absolutely nothing in that," he said.

"Anybody that is reading into the fact that he doesn't have Labor on his signs and looking at that in the current context is just being absurd."

Mr Swan also reaffirmed his support for Mr Rudd to serve on the Cabinet of a re-elected Gillard Government.

"Julia Gillard has made the position absolutely clear there will be a position for him [Mr Rudd] as a senior minister if the Government is re-elected," he said.

"I do believe that he is an honourable person. I do believe he is doing everything he possibly can to see the return of the Government."