More than 9,000 airline workers have undergone specialist training to verify passengers hold proper UK entry documents before boarding flights bound for Britain, the Foreign Office has said.

The comprehensive programme, which includes staff from carriers such as Wizz Air, Jet2 and Lufthansa, and stretches over 39 countries, forms part of Government efforts to strengthen border security and enforce the law on illegal migration.

Officials have labelled the scheme a "vital new shield" in UK border operations.

The industry-wide programme has been delivered through both online and in-person sessions as part of the new Electronic Travel Authorisation (ETA) and eVisa system, which require European travellers to register online before entering the UK.

The move forms part of efforts to strengthen border security and enforce the law on illegal migration

Training sessions have been concentrated in known migrant pathways like Greece, Italy, Malta and Albania.

The digital system is said to mark a major modernisation of UK border controls, specifically designed to prevent "risky" individuals reaching British soil.

UK diplomats across the continent have been told to raise these changes directly with their hosts - while public communications campaigns are being laid out to ensure European citizens understand the new entry rules.

The eVisa system allows visa holders to instantly check their entitlement to public services, work or rent property.

The digital visas also reflect changes in their legal status in real-time, allowing the Government to take enforcement action against overstayers.

The digital system is said to mark a major modernisation of UK border controls

Alongside these, a series of returns agreements have been reached with European firms as part of a strategy to work with the private sector in tackling the UK's migrant crisis.

Foreign Secretary David Lammy said: "Tackling irregular migration demands cooperation across borders and industries to disrupt the pathways used by those attempting to enter the UK illegally.

"We're sending a clear message: Air travel simply isn't an option without proper authorisation and registration. Our borders are becoming more secure, more digital and more effective."

A British Airways spokesman said: "As a carrier, this kind of insight is extremely useful and absolutely critical for us as it will guide us in how to process our customer whilst complying with the UK laws.

'We're sending a clear message air travel simply isn't an option without proper authorisation,' David Lammy said

"Our stations feel more confident and prepared in using the ETA/eVisa system."

Labour said it has returned some 30,000 people since taking office, including a 23 per cent increase in enforced returns.

It has also sent out four of the largest returns flights ever, sending migrants back to countries across Europe, Asia, Africa and South America.