Scott Morrison has shrugged off claims he was out of the loop on budget timing, saying “it is as it is”.

Last week the treasurer maintained the budget would be delivered on 10 May, just an hour before Malcolm Turnbull announced it had been moved to 3 May.

Appearing on Ray Hadley’s program on radio 2GB, Morrison explained he had said the budget would be on 10 May because “at the time we were speaking there’d been no change to that arrangement”.

“The cabinet didn’t meet until 10am. That’s when the prime minister advised he’d been to see the governor general. That’s when I was advised of him doing that. For some months there had been contingencies to [move the budget to 3 May] but something’s not changed until it’s changed.”

Morrison said he had been clear if the budget needed to be brought forward it should be done by the first week of April and the change was made “well inside that timeframe, there were no logistical issues”.

“It is as it is. I was very transparent about that, the budget is on 3 May and I look forward to bringing it down.”

He conceded the record showed he was not part of the small circle in the know about the prime minister’s trip to the governor general, “but in terms of the planning of the budget, that’s something we’d been working through since early February”.

Hadley said cabinet secretary Arthur Sinodinos, employment minister Michaelia Cash and attorney general George Brandis had all known about the plan.

Asked whether he was left out of the loop, Morrison said “in terms of the overall scheme of what we were attempting to do – obviously I had been part of that planning for some months; but the final decision, going to see the governor general and being across the constitutional issues, they’re things for the attorney general”.

Sinodinos was informed because it was his job to organise the cabinet meeting and Cash because she had carriage of the Australian Building and Construction Commission bill, he said.

Asked whether he would invite former prime minister Tony Abbott to campaign in his electorate of Cook in Sydney’s Sutherland Shire, Morrison said “I get on pretty well with the Shire”.

“I don’t get too many people coming down to campaign with me, I find that the Shire and I get on just fine. And I have a new area coming into my electorate, just across the Georges River and I’ll be campaigning over there.”

Hadley summarised the answer as “a long-winded no”. Morrison replied: “[Abbott] hasn’t come in elections before either ... he did come to functions when he’s been the prime minister before elections.”

Hadley gave Morrison a tip to leave the current and former prime ministers out of his election campaign, saying keeping Turnbull away would be “a really good idea if you want to be re-elected”.

Morrison said: “I have no plans for the prime minister to visit the Shire ... I tend to make sure we wash our own face down in the Shire, that’s what we’re like”.