The ex-employees entered the store at 6:45am and say they intend to stay there until Thursday.
Shop steward Jane Crowe, two ex-employees and three supporters were arrested at the Debenhams Henry street store in Dublin at around 8am after they entered their former workplace.
Employees say a redundancy package offered to them at the end of last week is an 'insult' and are calling for four weeks pay for every year served.
Speaking to RedFM News from inside the Patrick street store, Valerie Conlon says they expected that Gardaí would become involved: