Singer Sinead O'connor has joined Irish republican political party Sinn Fein and immediately called for its leadership to step down.

The Nothing Compares 2 U hitmaker announced on Monday (08Dec14) that she has signed on with the party, long believed to be the political wing of the Irish Republican Army (Ira).

However, in a barely-disguised reference to the Ira and its terrorist campaign of the 1970s and '80s, she insisted she wants a shake-up at the very top of the organisation to remove anyone born before 1983 who could be associated "with frightful things".

In a post on her page, O'Connor writes, "I joined Sinn Fein today. Because resolving issue number one is the way to resolve all current issues. Issue number one is we don't own our country. I might not even be the kind of person they want, because I'm gonna (sic) write here that I feel the elders of Sinn Fein are going to have to make 'the supreme sacrifice' and step down shortly in the same way the last Pope did.

"It was the smart thing for him to do because his association in people's minds with frightful things meant the church were losing bums on seats, if I may use a showbiz term. And now they have barely a seat to spare. Pure cold business. There'd be a zillion per cent increase in membership of Sinn Fein if the leadership were handed over to those born from 1983/1985 onward and no one associated in people's minds with frightful things.

"Frightful things belong where they are now, in the past. That increase would resolve issue number one. Ergo all current issues would be resolved. People are open to it now. A brand new country. Run by everyone of every nationality who lives in all of it."

O'Connor was hit was a barrage of responses to her controversial move, many of them slamming her for joining "a former terrorist organisation", but she is unrepentant, replying, "For anyone who is confused, Sinn Fein is no longer associated with the use of violence."