Here are the paragraphs on immigration detention from each Party manifesto.
ILLEGAL IMMIGRATION AND
There will be no amnesty for illegal immigrants.
We will increase the number of immigration
compliance and enforcement teams. Foreign
criminals will not be granted a visa to enter the
UK. Migrants who commit crimes resulting in a
custodial sentence will have their visa revoked and
be detained until they are deported.
The UKIP Manifesto 2017 page 34 para 1