Treasurer Scott Morrison says he won’t be Santa or the Grinch come budget time – he’ll just be responsible.

Attempting to make a splash on his first day in the top job with Malcolm Turnbull travelling to Europe, Acting Prime Minister Michael McCormack foreshadowed a big infrastructure spend in the May 8 budget.

“Scott ‘Santa Claus’ Morrison will be announcing some goodies,” he told The Daily Telegraph.

“There’s going to be some exciting projects elsewhere that have been called upon for many years that will be realised by this budget. We want people to cheer this budget home.”

But Mr Morrison played down the suggestion it will be a giveaway budget.

“I’m not Santa Claus – it won’t be Christmas in May – but I don’t intend to be the Grinch either,” he told ABC radio on Tuesday.

“What we will have is what we’ve always produced, and that is a responsible budget with measures the country can afford that are about investing in a stronger economy.”

Mr McCormack said the budget would allocate “a record spend” in excess of last year’s $75 billion for road and rail projects, and promised that no state or territory would be left out.

But Mr Morrison said his biggest single infrastructure announcement had already been made public – $5 billion for a rail link from Melbourne Airport to the CBD.

Shadow treasurer Chris Bowen joked the pre-budget preparations are “all going well”.

He agreed with Mr Morrison that he is no Santa Claus, having pursued increasing income tax for millions of working and middle-income Australians through a Medicare increase, axing the energy supplement for two million Australians, and raising the pension age to 70.

“All we have seen from Scott Morrison on tax thus far is the Christmas Grinch,” Mr Bowen said in a statement.

But Mr Morrison again indicated there will be personal income tax cuts in the budget, saying there will be a very strong focus on middle-income Australians who have “really been doing it tough”.

“We know there are things we can do to assist them at this time and going forward and we flagged that last November, we’ve been working steadily on it for months and months now,” he later told reporters in Canberra.