It might be a glimmer of hope for the battered travel industry.

The European Commission has set out plans for a 'Digital Green Certificate', providing proof of vaccination, and showing test results for those not yet inoculated.

Brussels will also work with international organisations to ensure the system works beyond EU borders.

The news will be a relief to firms like Germany's TUI - the world's biggest holiday company.

It recently sunk to another quarterly loss, posting a deficit of around 830 million dollars.

TUI communications chief Aage Duenhaupt says the passes are welcome news, but only part of the solution:

"As long as the option remains to keep testing, and we believe you should be able to go on holiday with a test then if there is testing and a vaccine pass there should be nothing standing in the way of freedom of travel."

EU leaders agreed last week to work on vaccine certificates, with southern member states like Spain and Greece desperate to restart mass tourism.

But countries including France and Belgium have said it's unfair to allow travel only for the inoculated.

Outside the EU, the UK government said Wednesday that it too was considering vaccine certificates as a way to unlock access to travel and hospitality.

There is almost certainly pent-up demand.

When Germany recently removed parts of Spain and Portugal from its quarantine list, there was a surge in travel bookings.

Firms like TUI hope the green passes will spark an even bigger rush for the departure gates.