Burnley: 6.6% Muslim (2001)
Calderdale: 6.8% Pakistani (2011)
Derby: 5.9% Pakistani (2011)
Hyndburn: 7% Pakistani (2011)
Kirklees: 10.1% Muslim (2001)
Pendle: 13.1% Pakistani (2001)
Peterborough: 9.4% Muslim (2011)
Slough: 17.7% Pakistani (2011)
Tower Hamlets: 32% Bangladeshi, 34% Muslim (2011)
Walsall: 25% Muslim (2001)
Woking: 6.7% Muslim (2004)
(Some surveys only supply ethnic - not religious - demographics: hence the fluctuation between “Pakistani” and “Muslim”.)
“Reports from the campaign trail in Oldham had suggested Labour was haemorrhaging votes among its traditional white working class supporters, horrified by what one commentator called the party's transformation into a 'poncified' party of middle class Metropolitan liberals.”
"It means effectively - in some of these seats where people don't speak English, but they're signed up to postal votes - effectively the electoral process is now dead."
Since the Labour leader is against military intention in Syria, that would have also played well to Rochdale's (Sunni)Muslims. However, Mr Corbyn and Rochdale's Muslims will have very different reasons for being against military intervention in Syria.