What is the name of the UK rule requiring drivers to keep a safe distance from a cyclist when overtaking?

The UK rule requiring drivers to keep a safe distance from a cyclist when overtaking is Highway Code Rule 163.

Rule 163 tells drivers to give vulnerable road users, including cyclists, as much room as they would give a car when passing at speed. It also states that drivers should leave at least 1.5 metres when overtaking cyclists at speeds up to 30 mph, and more space at higher speeds.

The Highway Code contains guidance and legal rules. Some provisions use words such as “must” or “must not” because they reflect legal requirements; other advice may be advisory but still describes safe, responsible driving. The rule is designed to reduce collisions and dangerous close passes.