"huge uncontrolled levels of immigration". Let's put some actual numbers to this. Net immigration in 2025 was about 170k people, over the next 10 years projections are for about 2.2 million net immigration. So that's about 3-4%. However, UK population is shrinking without immigration so net population growth with immigration is about 1.7 million.
Not sure if that matches a definition of huge, but it's important to note that with a shrinking population without immigration the UK would be in serious economic trouble (like every country). This is even more exaberated due to the aging population that the shrinking population implies.
Immigrants like always are the convenient scapegoat that is being used to distract from the increasing gap between the rich and everyone else.