The question has been asked more than once in recent days, as Labor's campaign roadshow rolled on with what should be one of its main attractions firmly out of the spotlight.

Tanya Plibersek hasn't been absent during the federal election campaign - she's appeared regularly on television.

But nor has the popular education spokeswoman been on the frontline, even when Anthony Albanese's bout of COVID-19 forced the Labor frontbench team to step up and share the campaign load.

As arguably the most popular and recognisable member of that bunch, keeping Plibersek off centre stage was bound to prompt rumour and speculation.

The former deputy leader ruled herself out of the race to replace Bill Shorten after the 2019 election defeat, but she'd be among the favourites to seize the top job if Labor loses on May 21.

There have been rumblings Plibersek has been sidelined to make sure she doesn't steal the limelight from Albanese, while at the same time raising her own, already high profile.

Hence the questions, where's Tanya? Where's Tanya?

On Wednesday morning, 23 days since Scott Morrison called the election, she appeared.

There was no apparent tension, only smiles and laughs, Plibersek and Albanese watched trainee chefs cook apple tart-filling during a visit to a TAFE campus in the hyper-marginal seat of Chisholm in Melbourne's eastern suburbs.

But having stepped out of the kitchen and into the furnace of the daily campaign press conference, it wasn't long before the question was asked.

"Ms Plibersek, have you been shafted?" a reporter asked.

The response?

Laughter.

Far from being "shafted", Plibersek said she had already visited more than 20 electorates and done 30 media appearances in the first half of the campaign.

"Not a single person has stopped me in the street and asked me the sort of question that you just asked," Plibersek said.

Albanese then stepped in with a very pointed question of his own.

"I've got my education spokesperson [Plibersek] here. Who is Scott Morrison's education spokesman?"

It is a good question no one can quite seem to answer.

Alan Tudge would of course be, but he resigned from cabinet following an internal probe into a workplace affair. The report found "insufficient evidence" to support the allegations against the minister.

But Tudge remains in cabinet, the Prime Minister says, and would return as education minister if the Coalition is re-elected. But that's only if he wants to return, Morrison says.

Trouble is nobody seems to be able to find Tudge to be able to ask him the question.

In the meantime, Stuart Robert is acting education minister. We think.

Tudge isn't the only missing minister. NDIS Minister Linda Reynolds, whose reputation has never recovered from the "lying cow" affair, has made only rare appearances.

It remains confounding that Labor haven't used Plibersek more during the campaign.

Same goes for Bill Shorten, aged care spokeswoman Clare O'Neil and industry spokesman Ed Husic.

If long-held personal grudges, factional politics or ego are the cause, then Albanese's camp need to ask itself if it is willing to risk losing an election, and consigning Labor to another three years in opposition, for no good reason.

But let's be clear, if there's one party with problems in its ranks, it's not Labor.

It's the party, to use Albanese's words, with ministers in "witness protection".