British Airways was caught up in a new row yesterday over the scale of the missing baggage mountain at Heathrow caused by the chaos at Terminal Five.

The airline claimed on Sunday night that 15,000 bags were being stored at the airport after missing their flights because of the failure of the automated baggage system.

But Jim Fitzpatrick, the Aviation Minister, said in the House of Commons yesterday that the true figure was 28,000 — almost double BA’s claim. He said that it would take up to a week for the bags to be reunited with their owners.

Willie Walsh, BA’s chief executive, said yesterday that the number of bags was 19,000.

Mr Walsh admitted that Terminal 5’s opening day had been a “disaster” telling Sky News: “It is a fantastic facility, we can make it work. But we got it completely wrong on day one.”

A spokesman for the airline said: “Some bags are going to Gatwick airport for reprocessing and being flown from there, going by road or being returned to Heathrow.”

Referring to Mr Fitzpatrick’s figure of 28,000, the spokesman said: “It’s not a figure we recognise. It could have been that a cumulative figure was referenced that didn’t allow for those bags that have been taken out of temporary storage and have already been reunited with their owners.”

Last night the Department for Transport said that its figure was based on information provided by BAA, the airport’s owner, and was correct at 10am yesterday. A spokesman suggested that the discrepancy between the BAA and BA figures could be due to different counting methods.

Earlier Mr Fitzpatrick said that passengers using the new £4.3 billion terminal had suffered “an unacceptably poor experience”. He also said that BA should abide by the rules on compensating passengers after it emerged that the airline had misled passengers about their entitlement. Mr Fitzpatrick was speaking as BA had to cancel a further 54 flights at Terminal 5, with a further 50 due to be axed today.

He said that he had visited the terminal and had seen “just how devastated individual staff members were”. He added: “The damage to Heathrow is damage to UK plc.”

One of the passengers who lost bags was Vuk Jeremic, the Serbian Foreign Minister, who complained about his experience to David Miliband, the Foreign Secretary, at a meeting in Slovenia at the weekend.

Mr Miliband did not name the minister but wrote in his blog: “His bags are nowhere to be seen and it was whispered that it might take weeks. He asked me to pass on a message to BA/BAA: ‘For goodness sake, get your act together’.”

Analysts at Citibank forecast that the disruption was likely to cost BA up to £25 million.

Other analysts said the final bill could be £50 million, with many people put off flying with BA.

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