Illegal entry means entering, or seeking to
enter the UK unlawfully in breach of the immigrations
laws. It is an offence to enter the United Kingdom
without entry clearance or leave. Also, if a
person remains in the United Kingdom after the
period of leave granted has expired, for example,
working or having recourse to public funds when
prohibited to do so under the terms of leave.
These offences are punishable by imprisonment
or a fine.
People who are in the UK but who cannot establish
a right to remain under the immigration rules,
or otherwise, and who cannot persuade the immigration
authorities to exercise discretion to allow
them to stay, can be required to leave. If they
do not leave, they can be arrested and detained.