A DUP assembly member has told Senator Cecilia Keaveney to drop any plans for an interpretive centre at a British Army base in his constituency.
Ballykinlar, County Down, is the site of a post-Easter Rising internment camp - where former Taoiseach Sean Lemass and Senator Keaveney's grandfather, James, were both interned.
Speaking in the Seanad, Donegal Senator Keaveney said a small interpretive centre at Ballykinlar, perhaps in a reconstructed hut, could help teach young people about Irish history and how to learn from the past.
She has asked the Republic's minister for arts, sport and tourism, Martin Cullen, to explore the Ballykinlar possibility with his British counterpart.
But DUP assembly member, Jim Wells, said Senator Keaveney could commemorate all she liked in the Republic but should not try and dictate to the British authorities.
The British government had always treated prisoners with humanity, he said.