Malcolm Turnbull edged around speculation he is fast-tracking the budget, only to walk into a confrontation with a South Australian voter about the state of the economy.

Key points: Turnbull confronted by SA voter asking about jobs, economy

Turnbull confronted by SA voter asking about jobs, economy PM says election will be held in "latter" part of year

PM says election will be held in "latter" part of year Tony Windsor tipped to announce candidacy for New England seat

Mr Turnbull travelled to the South Australian town of Whyalla to announce an upgrade of rail lines to assist operations at the local steelworks.

Despite senior ministers confirming the Government is considering bringing forward the budget by a week, the Prime Minister told reporters it was still on schedule for release on May 10.

The option of an earlier budget date is considered a way of clearing the path for a double dissolution election on July 2.

But voter Raylene Mullins stole the limelight. As journalists were wrapping up their questions, she stepped forward to ask some of her own.

The self-described Liberal voter secured almost four minutes of one-on-one with the Prime Minister and raised concerns about free trade agreements, international imports and the future job prospects for the next generation.

"Where are our grandchildren, their children and their children going to work?" Ms Mullins asked.

Mr Turnbull responded that the train line announcement was a measure to help sustain jobs in the region, in particular at the local steelworks.

"This is a huge investment in the future of this plant," Mr Turnbull said.

"I understand your concern, I really do. But our future is bound up with open markets."

Ms Mullins, a regular local radio talkback caller, went on to warn she was considering casting an "informal" vote.

"Do the proper job we all want you to do," she requested.

Mr Turnbull asked her to consider voting for the Liberal Party.

"Don't vote informal because that's a wasted vote," he replied.

She later told reporters she had been tipped off that something was happening when she spotted an ABC van while she was out walking her dog.

"There's not enough people like me who are prepared to speak up," she told reporters afterwards.

"That's what the Government needs … people to speak up and sort out all the nonsense that's going on."

Timing speculation 'a fascinating sport'

Earlier, Mr Turnbull tried to shrug off speculation about budget timing as a "fascinating sport", saying the election would be held in the "latter" part of the year.

"The budget is set down for May 10, and that's what we are working towards," he told reporters.

Coalition senator John "Wacka" Williams encouraged the Prime Minister to closely consider dissolving both houses if the parliament votes down legislation to reinstate the building and construction watchdog.

"The ABCC is a very important bill. I think it's got to pass Senate to clean up the corruption in the union industry and especially in the building industry," he said.

"If that is rejected by the Senate I think it's essential we have a double-dissolution because we simply can't get our program in place."

Queensland LNP senator Ian Macdonald cautioned that an early poll — and the eight-week campaign beforehand — would be difficult.

"Were it my decision, I wouldn't go early. I don't think people like early elections unless there's some real cause, some issue that needs to be resolved very quickly," he said.

Windsor flags bid to depose Joyce

The major parties are already in election mode and political rivals in key seats are starting to emerge.

Tony Windsor told Lateline he would make an announcement regarding the New England seat on Thursday morning. ( ABC: David Lipson )

Former crossbench king-maker Tony Windsor all but confirmed on Wednesday night he will run for his old New South Wales seat of New England, telling Lateline he cared about his grandchildren's future, and adding: "that's the question I have to answer: Do you care enough to really get into this, and I think I do".

Mr Windsor stepped out of federal politics before the last election, and the seat was won by long-term rival and now-deputy Prime Minister Barnaby Joyce.

He has long foreshadowed a fresh tilt at the Lower House, but is not publicly confirming his intention to run.

A spokesman for the Deputy Prime Minister responded, saying: "We live in a democracy and anyone is free to run. Mr Joyce looks forward to Mr Windsor's announcement of his intentions."