The UK has officially downgraded the terror threat to the nation from 'critical' to 'severe' and has cautiously eased the restrictions on air passenger hand-luggage introduced last week.

Under new guidance issued this morning, one small item of hand-luggage, which can contain most items apart from liquids and gels, is allowed. But major airport operator BAA is insisting it needs another 24 hours to implement the new rules.

The private company plans to start operations under the new regime at 04:30 tomorrow, saying it cannot brief security staff who are currently off-duty any earlier.

It has, however, managed to introduce new rules permitting widespread purchases in the duty-free shops in its terminals that are a major source of revenue for it.

Even under the relaxed rules, the size of hand-luggage permitted is only about half the size of that normally allowed. But laptops and other electronic devices are acceptable again, subject to close examination.

The change in the threat level indicates only that the authorities regard an attack as no longer imminent - it is still considered likely.

Source: Flight International