There are a multitude of factors.
Lowest common denominator.
As the poem goes:
First
they came for the Communists
And I did not speak out
Because I was not a Communist
Then they came for the Socialists
And I did not speak out
Because I was not a Socialist
Then they came for the trade unionists
And I did not speak out
Because I was not a trade unionist
Then they came for the Jews
And I did not speak out
Because I was not a Jew
Then they came for me
And there was no one left
To speak out for me
In the fascism scheme, you start at the bottom of the Social caste system, in ostracizing. In the case of the UK, that would be Muslims and more specifically British Pakistanis. They are the easiest to demonize and built hatred against, and they are most degrees removed from WASPs both in terms of ethnic origins and religion, and they exist in numbers to where they are seem as a threat by the nativists.
If you try to sell fascism, and you start in the middle instead of the absolute bottom, b/c if you start in the middle you have to oppose everyone middle to down, and thats harder element to sell.
Often times you will see many who are in the middle or towards the bottom but not at the complete bottom, many of them in an attempt at self preservation by trying to show the nativists that they are "one of the good ones" or b/c they also have animosity towards other groups, they attempt to join in with the Nativists, this accounts for the politics of the likes of Shaun Bailey and Kemi Badenoch who will lean into their christian identities and separate themselves from other BAMEs in courting WASP support(SAAAR, SAME TO SAME SAAAR), you see a similar phenomena with some Hindus and to a lesser degree even Sikhs.
thats one element, the other element is that much of the right wing surge is astroturfed and funded by the same people who fund things like the Henry Jackson society and other Zionist causes.