A Fine Gael senator has criticised Sinn Féin for selling clothing featuring the slogan: 'IRA Undefeated Army'.

The t-shirt is one of many for sale on the party's website.

It shows masked men pictured in the letters 'IRA' with the words 'Undefeated Army' underneath.

It is described as "a tribute to the men and women who led the struggle against British occupation of Ireland."

But Fine Gael Senator Joe O'Reilly told Newstalk Breakfast this approach to politics is no longer acceptable.

"I think that the entire justification of violence now, and justification of the IRA campaign... that when you retrospectively justify that campaign now, you implicitly - and you by extension - feed into the dissident agenda - feed into the view that if so much is achieved in the past, this should continue into the future.

"I think a political party has to abandon this kind of thing, and I think it's important it stops.

"There's a cohort of young males who have not experienced The Troubles, who have not been part of a generation that knew violence - and this has the potential to influence them, it has the potential to put them on that road.

"I don't think there's a justification for that kind of thing in the present context at the present time".

"I think it's important as they propose to enter government, as they go on with the politicisation and involvement with democratic politics it is important that they for their sake - and indeed for the wider sake of our community - that they abandon these.

"I think it's important hat the glorification of violence through a potentially vulnerable section of people is stopped; I think it's important that a kind of a retrospective justification of violence is not fed into supporting the current dissident agenda".

"If you like it's evolutionary, it's an important staging post and I think it should be done".