Immigration Acts
The Immigration Act 1971 is the source of Home Office powers to make decisions about who can enter and stay in the UK and who can be removed or deported. It is amended very regularly by other immigration acts, some of which cover other matters, including appeal rights.
One of its key principles is that people who have the right of abode are free to live in, enter and leave the UK, "without let or hindrance"
People who have the right of abode are British citizens and others who have a certificate of entitlement to the right of abode, or a passport describing them as a British subject with the right of abode.
Those who do not have the right of abode, and who are not European Economic Area or Swiss nationals, need to apply for permission to enter or stay in the UK. This is called leave to enter or leave to remain or, more generally, leave.
EEA nationals are EU nationals plus nationals of Iceland, Liechtenstein and Norway
The Immigration Rules provide details of the requirements they need to meet.
The Immigration Act does not need to be amended in order to change the requirements a person must meet, but the Immigration Rules will change.
