The Labour Party says there is nothing wrong with a series of bus shelter billboards, which ACT MP Ken Shirley claims breach parliamentary rules.
Mr Shirley has written to Parliament's Speaker over billboards which display the message "You're Better Off With Labour" and carry the Labour Party logo along with the Parliamentary crest.
Mr Shirley said yesterday there were rules on what the Parliamentary crest could be used for.
He said he had written to Speaker Margaret Wilson because she was responsible for upholding Parliament's rules.
But a spokeswoman for Prime Minister Helen Clark said today the billboards followed a format that was used widely after last year's budget.
Those advertisements had been used without problems.
The billboards were paid for from the leader's budget, she said.