The Reserve Bank of Australia will begin paying dividends to the government in August, the governor, Glenn Stevens, has revealed because an $8.8bn grant from the treasurer, Joe Hockey, means the bank no longer needs to retain profits to build up its reserve fund over time.

The surprise grant was a big factor in the increase in this year’s deficit to $47bn from the $30.1bn forecast in August and Labor has claimed it was a “stunt” to make future Coalition budgets look better. It insists the bank had not asked for that sum.

Stevens told the House of Representatives standing committee on economics that the bank's “desire for a stronger capital position were already a matter of public record” so there had been “no need for me to go to the new treasurer and pound the table and say ‘you have to do something here’”.

But the size of the grant had been a decision of the government.

“I didn’t go there saying ‘could I please have $8.8bn, sign the cheque now’. It was an issue that was clearly on the table [at his first meeting with then treasurer-elect Hockey],” Stevens said.

He said it would have taken six to eight years for the bank to achieve its ultimate desired level of capital in the reserve fund – 15% of its assets at risk – by retaining profits each year.

“I think any board would welcome a way of completing that journey faster … it’s a matter for the government if the use of $8.8bn in that way as opposed to another way is the best course, that’s not for us to judge,” Stevens said.

And he said it had been Hockey’s decision to make a grant that took the bank straight to its ultimate 15% rather than its interim 10% target.

“The discussion was ‘do we go to 10 or do we go straight to the long-run target?’ The conclusion was the Treasurer felt we go straight to the long-run target,” he said.

“I don’t think I could say it was ever my opinion it was mandatory it be done in one go … it was extremely important it be rebuilt as quickly as we could manage.”

Steven told the committee “....faster is better, I’ve never said to do it instantly was critical”.

He said the grant, which is due to be made before June, would take the reserve fund to a level where “we can be very confident the bank is very strongly capitalised and has an undoubted capacity to deal with whatever shocks might come along”.