Simon Calder: 'Rather unusual'? You can say that again

Perhaps it was Tony Douglas's choice of phrase that pushed Willie Walsh over the brink. On Saturday afternoon Mr Douglas, who is managing director of Heathrow, told Sky News that passengers were experiencing "rather unusual travel arrangements".

It is, indeed, rather unusual for passengers using Europe's busiest international airport to be told that their flight has left without them because they had failed to get through the security queue in time - or to find that the aircraft and crew that was waiting for them is among the 33 per cent of flights ordered to be grounded by Mr Douglas.

Heathrow's biggest customer is British Airways, whose chief executive is Mr Walsh. His unprecedented attack on his airline's landlord, BAA - which he accused of incompetence and poor planning - was not really aimed at Mr Douglas. Its real target was the Department for Transport, whose imposition of the most stringent rules ever on cabin baggage and passenger screening have brought Heathrow close to meltdown.

This morning hard-pressed security staff will remove passengers' copies of The Independent and anything else beyond the bare minimum of passport, ticket, wallet and keys. Close by Boots dispenses a wide range of chemical products. And at Dixons, travellers can also replace the laptop or camera that has had to be checked in to the hold.

These self-contradictory rules might merely look ridiculous, but for two serious consequences.

First, the insistence that every passenger receives a body search even if they have passed the usual metal-detector means the screening process takes four times longer. No-one in aviation believes that a Ryanair hop from Stansted to Spain is under the same threat as a US airline flying from London to Washington. Yet Medit- erranean holidaymakers have to suffer the same draconian regime as transatlantic travellers

The second worry is that vast resources are being deployed to implement this ludicrously blunt strategy, reducing the focus on other equally terrifying threats - specifically the use of shoulder-launched missiles to shoot down civilian aircraft.

Meanwhile, terrorist groups will be taking comfort from the way in which even a failed alleged plot can bring Heathrow.