The post you are reporting:
Blimey, this Forum's right-wing? Who said that!
As for the question you've been given, spaceyat, it's begging to be taken apart. E.g., the notion of 'blame' carries a note of political judgment you wouldn't expect to see: perhaps 'a cause of' or 'a contributary factor in' might have been more, er, neutral. Has there really been 'an increase in fascist and right wing ideologies in the UK'? Over what time-period? What's 'right wing' exactly? How's 'ideology' being used here: a political grouping or party, a set of ideas?
Anyway, taking the question for what it is, I'd answer 'no'. Why? First, there were more 'fascists and right-wingers' about in the 70s, so there hasn't been an increase in their numbers; there may have been an increase in the number of right-wing political parties, groupings and factions, though, and in their visibility because of social media and sympathetic mainstream media. (And if you include the Conservative Party, its membership is falling.) Second, post hoc, ergo propter hoc: i.e. even if it could be proven that there has been an 'increase in right wing ideologies', and that this phenomenon came about after the introduction of policies that might be described as 'multicultural', you'd still have work to do to establish a causal connection, or risk committing a logical fallacy (y succeeded x, therefore y was caused by x). Suffice to say, I don't believe causality is easily established.