Labour Party leader Phil Goff says the party has not done a deal with the Greens in the Wellington electorate of Ohariu, held by Peter Dunne.
Green Party MP Gareth Hughes, who is standing in the seat, is campaigning only for the party vote. He has said he would be pleased if that helps Labour's Charles Chauvel.
Mr Goff says Labour works closely with the Greens, but there have been no formal discussions about arrangements in any electorates.
The National Party has said its candidate in Ohariu, Katrina Shanks, will campaign for the party vote to help Peter Dunne retain the seat.
Mr Dunne's United Future Party is a support partner to the National-led Government.