Members of the IMPACT trade union at Sligo General Hospital have voted overwhelmingly in favour of industrial action, up to and including a strike.
Staff at the hospital are angry over what they say are unilateral decisions by management at the hospital to end automatic entitlements to sick pay and agreements on attendance arrangements.
Talks between the HSE and the union get underway on Wednesday.
IMPACT's Assistant General Secretary in the North West Richie Carrothers said he was expecting the discussions to be tough.
"It think that it's indicative of just how people feel on the ground and the management could get no other conclusion from this that the meeting we will be having with them on Wednesday is either make or break if they wish to avoid industrial action,” Mr Carrothers said.