According to the new law to protect cyclists, the driver needs to leave a minimum distance from a cyclist when overtaking or travelling alongside the bike or they could receive a fine. This would be £100 and three points on the licence for being too close to a bike on the road.
So, how close is too close? According to experts, the recommended distance between car and cyclist is 1.5 metres. If you are caught within this distance, then you face the potential of a fine and points on your licence, to the same value as speeding. This has replaced the previous recommendation in the Highway Code which merely said that drivers should leave ‘plenty of room’ when overtaking someone on a bike.
Rule 163 also adds that drivers should leave ‘as much room as when overtaking a car’ when they overtake a motorcyclist, cyclist or even a horse rider. Other reasons that drivers could receive the new penalty will be straying into cycle stop boxes at traffic lights and failing to give cyclists going straight ahead priority at left turns.
https://www.petrolprices.com/news/driving-close-cyclist-leads-fine/What are the rules/law in other countries?