BAA is refusing to pay fines of £1.7 million for keeping passengers waiting too long in security queues at Heathrow and Gatwick, claiming the alleged liquid bomb plot made delays inevitable.

The airport operator is being rebuked and warned over its future conduct by the Civil Aviation Authority for deciding unilaterally to withhold agreed payments to airlines.

The regulator accuses the newly Spanish-owned company of an “inappropriate course of action” and says it will face close scrutiny from now on.

BAA was widely criticised for subjecting passengers to cancellations and long queues when tough security measures were imposed by the Government following the discovery of the alleged bomb plot in August.

In a surprise disclosure that will further anger airlines, the airports operator admits it has failed to recruit any extra security staff at Gatwick.

It warns that long delays are likely to continue through Christmas to the end of the year as cold weather means more passengers will be wearing coats and jackets that will have to be put through X-ray machines.

New European security rules imposed from Monday, forcing everyone to put liquids such as toothpaste and shampoo in clear bags which need separate X-raying, are also expected to add to waiting times.

The target is that 95 per cent of passengers must be checked within ten minutes. BAA has long struggled to cope. In the early months of this year, just 47 per cent of passengers were cleared on time at Heathrow Terminal 4.

BAA has asked the regulator to suspend security queuing fines at Heathrow and Gatwick from August to the end of December. It has already stopped paying the penalties and would only do so if forced. The maximum it could be fined for that period is £1.7 million.

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