Leaked emails report that ambulance drivers are having fuel rationed - as an industry leader described the crisis as "self-inflicted insanity".

One email, seen by Sky News, suggested that ambulances were being forced to join lenghty queues at petrol stations and restricted to a maximum of £50 of petrol.

Another email suggested that police and ambulance drivers were turning up to designated petrol stations to demand that fuel be held back for them.

In the same email, Chris Hunt, Director General of the UK Petroleum Industry Association, described the situation as "self-inflicted insanity".

The email from Mr Hunt to the Department of Energy read: "We are also getting reports that Police and Emergency services are turning up on DFS [disignated filling stations] and Non-DFS [non-designated filling stations] demanding priority and stocks to be held back on their behalf."