The warning comes as people in England who refuse an order to self-isolate could be fined up to £10,000.
People reported queues for attractions and traffic was gridlocked in Blackpool on Saturday.
The Labour leader tells the BBC testing problems make further Covid-19 restrictions "more likely".
Play was stopped for 15 minutes while attempts were made to remove "man of the match" Oscar.
The musician, who was also part of heavy metal band Uriah Heep, had been diagnosed with prostate cancer.