Depends how they're influxing. If they're seizing our homes and land by force and taking over our government, sure.
But as far as I can see, they're working for the NHS, running restaurants and shops and so on, and buying/renting homes that come up on the market like everyone else. London's Muslim mayor was elected by an absolute majority even though Muslims are only about 12% of the city's population.
Nobody is stopping Brits from doing Brit stuff - it's our own fault if we choose not to.
Far as I can see, what's done a lot of basic pubs in is a combination of lifestyle changes, people who don't like the smoking ban, and younger people wanting to spend time down the gym instead of drinking.
And pray tell, how does the influx of a muslim, non-alcohol-drinking population, influence this?