The Labor Party has reprimanded a candidate for handing out how-to-vote cards for the Greens at a pre-polling station.

Labor's Buderim candidate Elaine Hughes was photographed yesterday handing out the Greens how-to-vote cards as well as Labor ones at a pre-polling booth on the Sunshine Coast.

"It was just a mistake. I've apologised for it. I'm very busy," she told the ABC.

As to why, she said: "I really don't know... more out of tiredness".

Ms Hughes said she was sharing a table and the cards were bundled together.

The Greens are preferencing Labor in the seat, held by the LNP's Steve Dickson.

Labor leader Annastacia Palaszczuk said she did not know anything about the incident when asked about it on the campaign trail at Emu Park near Yeppoon in central Queensland this morning.

"Well I don't think that would be appropriate," she said.

In a statement, Labor campaign director Anthony Chisholm said Ms Hughes had been spoken to and has apologised.