PROTECTION FROM EVICTION ACT 1977 ss 1-3, RENT ACT 1977 sch 15 and CRIMINAL JUSTICE AND PUBLIC ORDER ACT 1994 ss.72-76 and HOUSING ACT 1985 sch 1, para 2.
It is a criminal offence to evict a "residential occupier" without due process of law (Protection from Eviction Act 1977, ss.1-3 and see CRIMINAL LAW ASPECTS/offences under employment legislation/eviction of ex-employee from accommodation ).
The important question is therefore whether the court will make a possession order/eviction order. The fundamentally important point here is normally whether the employee/former employee occupies the accommodation as tenant or as licensee.
Property owners can apply to the county court for an "interim possession order" against squatters. The order can be made ex parte, without the squatters appearing. If the court makes the order, uniformed police can arrest the squatters if they are still on the premises 24 hours later. There is protection for people who are wrongfully evicted as a result of an "interim possession order" (who can have the right to be restored to possession and to compensation - see Criminal Justice and Public Order Act 1994, ss.72-76, inter alia inserting a new s.7 into Criminal Law Act 1977 entitled "Adverse occupation of residential premises").