A five-week official election campaign is expected to begin within days, culminating in voters going to the polls on September 7.

The Federal Government’s mini-budget and recent policy changes have cleared the way for Prime Minister Kevin Rudd to visit the Governor-General to ask for an election.

The Opposition has been demanding Mr Rudd announce the polling day, arguing business confidence has suffered because of the wait.

Mr Rudd made it clear when he returned to the Labor leadership in June that he was not committed to sticking to the September 14 poll date set by former prime minister Julia Gillard.

On the trail: Prime Minister Kevin Rudd visits the Royal Prince Alfred hospital in Sydney. Photo: AAP

A federal election on September 7 would mean a referendum on recognising local government in the constitution on the same day.

The Government has been preparing for an election campaign with recent policy changes on immigration, carbon pricing and .

The updated budget sets the scene for a frugal election campaign ahead.

The update revealed massive revenue write-downs since the May budget, deeper budget deficits for the next three years and $17.4 billion worth of cuts and savings measures.

The Government says a substantial decrease in nominal GDP has had a major impact on expected tax receipts, leaving a $33.3 billion revenue black hole across the four years of the forward estimates.

Opposition Leader Tony Abbott visits St. Andrews Christian College in Melbourne as his party announces a Coalition government would match Labor on school funding. Photo: AAP

It also revealed that $879 million would be cut over four years from the aid budget.

Australia will boost its aid contribution to Papua New Guinea by $420 million in return for support of Labor’s plans to resettle refugees in PNG.

Aid agencies Oxfam and UNICEF have condemned the Government’s decision to slash foreign aid to pay for its so-called PNG solution.