The tenancy can be terminated by service of a notice to quit (NTQ) which expires at the end of a full period of the tenancy, if it is periodic.
If the tenancy is for a fixed term any NTQ can expire at the end of the term.
In the case of a contractual tenant holding over at the end of a fixed term tenancy, it is best to assume that the tenant will be treated as a periodic tenant and ensure that the notice expires on the correct day (and/or that an appropriate saving provision is added). The NTQ must give at least 28 days' notice and contain prescribed information (section 5 Protection from Eviction Act 1977).
In the conjoined appeals of Hounslow LB v Powell, Leeds C v Hall & Birmingham CC v Frisby 2011 UKSC, the Supreme Court considered the decisions made in respect of possession proceedings brought against two tenants with introductory tenancies and an individual with a licence to occupy premises under homelessness regime in H A 1996 Part V1. The Court considered proportionality, article 8 Human Rights Act 1998 and whether the Court could defer the maximum permitted period for possession under s89 HA 1980.
Prior to the case of Hounslow LB v Powell, Leeds CC v Hall & Birmingham CC v Frisby 2011 UKSC it was practically impossible for the occupant to rely on the public law/human rights defence unless circumstances were truly exceptional.
Tenancies/Licences which are exempt from the Protection from Eviction Act 1977
Prior to Powell/Hall/Frisby the position was clear. There was no need to get a court order to obtain possession. All the licensor/landlord had to do was terminate the licence or tenancy and regain possession, subject to Section 6 of the Criminal Law Act 1977 (which outlaws using or threatening violence to secure entry to premises).
The position is now far less clear for public sector landlords following Powell/Hall/Frisby.