Ben Bulben. Tourism Ireland

A controversial “No” sign on famous Irish mountain Ben Bulben is causing a stir ahead of the May 25 referendum on abortion in Ireland.

A gigantic “No” sign has been placed on the north side of iconic Irish mountain Ben Bulben by a pro-life group in Co. Sligo. The mountain was previously the home to political statements such as “H Blocks” and “Brits out” during the Troubles in Northern Ireland.

“It is a massive project and there are about 20 of us on the mountain at the moment involved in the operation. It is well-planned and well-executed, just as the government is planning to execute the future children of Ireland,” said Tommy Banks of the Sligo For Life campaign, adding that men started work on the sign at 4am on Thursday morning while women made tea and sandwiches.

Read more: Cillian Murphy urges men to vote in Ireland's abortion referendum

“We’re just saying no, it’s a big cry from the mountain to say no.”

The sign has stirred controversy by those who think it has defaced the mountain, an iconic Irish sight often featured in the work of W.B. Yeats.

Read more: Irish Americans are taking sides in Ireland’s abortion vote

Banks claimed, however, that the land used is commonage and that they had permission from all the landowners to erect the temporary sign.

While there has been general outrage from the Yes campaign about the move, some Irish Twitter users, of course, had to see the funnier side:

Do you think Ben Bulben should be used for political purposes? Let us know your thoughts in the comments section, below.