No need to blow this out of proportion, the recent smugglers were carrying HUNDREDS of kilos. Of course best to avoid any trouble, but small amounts clearly have not been prosecuted for decades. UK Customs has to refer drug offenses to the police, and they have published guidelines. Odds are your friend will at worst get a warning and spend hours at the airport being processed. Second time part with 80 quid. Smoking or vaping on a plane is another matter and will get you in more serious trouble, but then so would smoking cigarettes on an aircraft.

For personal use amounts:

Guidelines issued by the Association of Chief Police Officers (‘ACPO’) advise police officers to take an 'escalating' approach to the policing of cannabis possession. It outlines three possible responses for officers to take where they believe they have found an individual in possession of cannabis for personal use:

1. Cannabis Warnings

A person found in possession of cannabis for the first time can receive a cannabis warning if there are no aggravating factors (please see below). Where a police officer decides to proceed with a cannabis warning the individual should be warned that:

• a record of the investigation will be made at the police station;
• the offence of possession will be recorded against them, for statistical purposes, as a detected crime;
• this procedure does not constitute a criminal record.

2. Penalty Notice for Disorder (PND)

Where someone has already received a cannabis warning and is again caught in possession, then the police have the discretion to issue an on the spot fine ('PND') for £80.00. If the PND is paid within 21 days no further action will be taken and no criminal record will exist. A PND can be challenged, and if challenged will result in criminal proceedings at the Magistrates Court. Failure to pay will result in a fine for the original penalty plus 50% (£120) being registered against the defendant at their local Magistrates’ Court. A person has a right to refuse a PND but this will probably result in arrest.

3. Arrest

An individual who has received a cannabis warning and a PND and is caught again for cannabis possession should be arrested and taken to the police station. At this point, and depending on the circumstances, either the matter will be dealt with by way of charge, caution or no further action (including the possibility of issuing a further cannabis warning or a PND).

If a person is caught in possession for cannabis and there is one or more aggravating condition present then they may be arrested. The following are considered to be aggravating conditions:

• smoking in a public place;
• where there is a locally identified policing problem;
• if the person is aged 17 or under;
• someone considered to be vulnerable;
• if the individual is a repeat or persistent offender.