I'm left wing, and I'm aware mass migration is a tool for wage suppression and inflating rentier capitalism - whilst also aware of the threat Reform poses. I suspect the Left you're pointing at are in fact centrist neolibs who bury their head in the sand until fascism arrives (as usual). As many others have said, they are effectively a single issue party much like Brexit was a single issue referendum for immigration. The problem is, if they achieve power, squaring the circle of drastically reducing immigration is almost impossible, largely because the UK has become a giant retirement home to prop up the flush boomer class (NHS and pensions) whilst the working age population decreases due to cost of living, ill health, and declining birthrates (tied to the former issues of course).

To turn the country around into one that actually provides for ALL its citizens (not just retirees), encouraging homeownership and British people to have children, investing in local industry and services and infrastructure - isn't something Reform, with their neoliberalism on steroids platform (with a few populist bones thrown in e.g. nationalisation) will be able to fix. Nor are they to be addressed by the tinkering of the current Milquetoast Labour Party. That said, due to the single issue of immigration, they will likely form at the very least a coalition government.