UKIP is mainly a product of the Labour party policy rather than EU policy. Upon the expansion of the EU in 2004, the Blair government did not put any restrictions on freedom of movement[1] unlike Germany, France, Netherlands, etc. Predictably, the UK was drowned in a torrent of migrants.

UKIP is a nationalist party: they don't just want to be removed from the EU, but the EEA and the Council of Europe too.

[1]: https://en.wikipedia.org/wiki/2004_enlargement_of_the_Europe...