FIANNA Fail has put up posters in Belfast for European election candidates running in constituencies in the Republic.
Election posters urging people to vote for Pat 'the Cope' Gallagher and Mary Fitzpatrick have appeared in south Belfast.
Mr Gallagher is running in the Midlands North West constituency while Ms Fitzpatrick is contesting Dublin Central.
It is thought Fianna Fail is targeting university students from the Republic who live in Belfast.
A Department of Environment (DoE) spokesman said planning legislation does not require a political party - even from the Republic - to get approval for election posters.
Rules only cover the size, location and eventual removal of the posters. "The display of advertisements relating specifically to a pending parliamentary, European parliamentary, Northern Ireland Assembly or district council election do not, under current planning legislation, require DoE's express consent," the spokesman said. "This includes the display of European election posters even for Fianna Fail candidates who are not contesting a European seat in Northern Ireland."
The spokesman said the content of posters is regulated by the Advertising Standards Agency. "What does come under planning regulation is the size, location and when the posters are to be removed. "In addition, this year with the Giro d'Italia, new regulations have been introduced by DoE to ensure that any posters displayed along the route of the race from May 8 to 11 require the department's express consent."