The law when overtaking
1.5m is a minimum safe distance for overtaking in slow moving traffic. If you cannot allow the minimum distance, do not overtake until you can. At speeds of 30mph or above, the Highway Code recommends a car width may be needed to overtake safely.
Rule 139 of the Highway Code states “give cyclists at least as much room as you would a car when overtaking”.
Rule 188 of the Highway Code states “When passing a cyclist give them plenty of room”. If they look over their shoulder while you are following them it could mean that they may soon attempt to turn right. Give them space and time to do so.