Workers at one of Cork’s busiest Tesco stores are striking over terms and conditions.
Staff at the Douglas store voted unanimously last week for strike action.
Tesco is due to open the new store in Douglas on Friday.
Earlier this month, several long-serving staff at the old store received letters telling them to accept new terms and conditions or else be laid off.
Mandate has accused the company of is trying to bully staff and last week the workers voted unanimously for strike action.
85 workers began picketing the store from 8am.
In a statement, Tesco says it does not consider itself in breach of any agreements with Mandate.
It called on it not to proceed with the strike saying the matter has already been referred to the Labour Relations Commission.