Three parties have promised to remove election posters erected on the Giro d'Italia route – claiming the ban was flouted because of a mistake.
The DUP, TUV and NI Conservatives all say posters their activists erected along the route will be removed before the race.
Earlier this month Environment Minister Mark H Durkan announced a ban on posters on the Giro route during the races from May 8-11.
A caller to the Belfast Telegraph yesterday complained about a Conservative poster for Euro candidate Mark Brotherston erected in Templepatrick, as well as a poster for TUV leader Jim Allister on the A6 close to Antrim.
Both parties said the posters had been placed there by mistake and would be removed.
A Conservative spokesman said: "One of our teams did put a poster or two there by mistake. We're aware of them and they will be down shortly."
While a TUV spokesman said it would remove its rogue poster, he felt people were overreacting.
"This is a European election and the Giro is a European race; posters will also be up along the route in Italy, and are southern Irish political parties going to avoid putting posters along the route to Dublin?" he queried.
"The poster of ours in question was put up before the route was changed, it will be removed before the race."
Several DUP posters for its Euro candidate Diane Dodds have been erected in Glengormley. A DUP spokesman said they will be removed before the race.
Meanwhile, the PSNI said it had received four reports of theft/criminal damage to election posters in Belfast.
Police in Lisburn also received a report that election posters had been removed at Hillhall Road.
A PSNI spokesman said it was investigating the reports.
Alliance deputy leader Naomi Long (below) said a "significant number" of her party's posters have been stolen and she felt there was a "sinister element" behind it.
She said some of the posters were replaced by Union flags.
"Anyone who removes Alliance posters is clearly threatened by our determination to build a shared future for everyone," she said. "While the removal of these posters is an attempt to intimidate Alliance, like previous similar attempts where we came under pressure from bully boys, we will not be deflected from standing up for what we believe in, from taking our message to the electorate and representing those who have elected us.
"We have reported these crimes to the police and would encourage anyone with information to do likewise. Not only is it theft, but it is also a punishable offence to interfere with an election in this manner."
SDLP South Belfast councillor Claire Hanna also complained about a number of her posters going missing, while a DUP spokesman said several of its posters in Dungannon have disappeared from lampposts.
"This is a European election and the Giro is a European race; posters will also be up along the route in Italy, and are southern Irish political parties going to avoid putting posters along the route to Dublin? The poster of ours in question was put up before the route was changed, it will be removed before the race."