Rochdale does not have a 30% Muslim population. But the rest of what you said is soo true
from 2021:
Religion Number %
Christian 104,841 46.9%
Muslim 42,121 18.8%
Jewish 218 0.1%
Hindu 613 0.3%
Sikh 191 0.1%
Buddhism 398 0.2%
Other religion 675 0.3%
No religion 64,349 28.8%
George got 40% of the vote. An independent got 21% and the third was a Conservative at 12%
IMHO...this is the issue with a Parliamentary system, too many parties break up the vote. It only takes a demographic to vote as a block, like Muslims, to win elections. Christian’s and others are probably voting for various candidates.
With the ‘problems’ of a two-party system, this isn’t one of them.