Retailers in the North East of England are leading the crackdown on sales of alcohol to underage drinkers, according to a test purchasing company.

Serve Legal visited 4,016 UK stores between July and September. It found 87% of retailers in the North East who served alcohol asked for ID from its 18- and 19-year-old testers.

A spokesman said: "Our experience shows performance improves when staff are aware they will be randomly tested."