Chipping Barnet MP and shadow transport secretary Theresa Villiers led calls for an investigation into the Terminal 5 fiasco yesterday.

Following reports that some 28,000 bags have now been separated from their owners, Mrs Villiers described Heathrow as a "national embarrassment".

She said: "We need an investigation into what went wrong, we need to find out whether responsibility lies with British Airways or Heathrow's owners, BAA.

"Heathrow is our window on the world and it has long been a national embarrassment. This latest fiasco only adds to that."

Mrs Villiers also called on the Government to "knock heads together", claiming that transport secretary Ruth Kelly was "happy to sip Champagne at the opening ceremony and then run for cover" when things went wrong.

Yesteray BA cancelled 37 inbound and outbound flights of the 331 it was due to operate and a further 50 are expected to be cancelled today. This is on top of the 208 flights the airline was forced to scrap in the first three days of the terminal being in operation.

Nearly 24,000 passengers have now been affected by the disruption.

The airline was unable to predict when its full schedule would be operating, committing itself only to running a "progressively larger flying programme" at a time when many school holidays are about to start.