After months of disarray, it is now mandatory for “visa-exempt foreign nationals”, including British travellers, who are flying to or through Canada to obtain an Electronic Travel Authorization (eTA).

The eTA mirrors the US “Esta” programme, though with less onerous demands for information, and validity of five years, rather than two.

As with the Esta scheme, it has attracted online scammers who set up websites designed to look like the official portal. One Belize-based organisation is charging £80 for a process that should cost just C$7 (£4.20). The only legitimate site is canada.ca/eTA.

The scheme began in the summer of 2015 and was due to become obligatory from 15 March 2016. However, issues with IT forced the authorities to postpone the scheme until after the summer.

The government says: “The eTA requirement allows Canada to check that travellers are admissible before they board their flight, preventing those who are inadmissible from travelling to Canada in the first place.”