Labour Senator John Gilroy has announced he is withdrawing from the contest to be the party's candidate in the Ireland South constituency for the European elections.

Mr Gilroy was due to go up against sitting MEP Phil Prendergast, a former senator who assumed Alan Kelly's European Parliament seat when he was elected to the Dail in 2011.

It is understood Mr Gilroy, who is based in Cork, was unhappy that the constituency selection convention had been postponed from February 23rd to March 9th, which he believed would give rival parties a head start on Labour in the campaign.

However, party sources pointed out that Ms Prendergast, who is Tipperary based, had only recently buried her father, and claimed it was reasonable to delay by a couple of weeks.

Mr Gilroy announced his decision to the parliamentary Labour party this afternoon.