depth

Just a quickie guy's..:thumbup ( I really hope there not several ansaws!) What is the Uk legal minimal tyre depth...... I've seen 1mm a few times yet I have been told 3mm only today buy a dealer! I take it the front and back would be the same?...:rolleyes

Hi guys, having a wrangle over a s/h tyre, how much tread does a new one have? The ebay one that is sposed to have "a good 5mm+" turned out to be more like 2. They have offered one with 4mm now in exchange... Dilemma