It's after the Irish Nurses and Midwives Organisation rejected proposals to address what it says is 'a recruitment and retention crisis' in the health service.
SIPTU has also confirmed that its members will be supporting INMO colleagues.
General Secretary of the INMO Liam Doran says the proposals that were put forward this week were 'too little too late':
SIPTU had been hopeful that progress could be made in the dispute.
But the union has confirmed it will be supporting colleagues in the INMO.
