British Airways has postponed until June the planned move of its long-haul services to Terminal 5 because of the fallout from the building's disastrous launch.

The delayed transfer of the services from Terminal 4 to the new £4.3 billion home is the latest blow to BA, which has been forced to cancel hundreds of flights in the days after T5 launched after its "state-of the-art" baggage-handling system imploded.

Most humiliatingly, BA had to admit that it was sending thousands of bags by coach to be sorted in the northern Italian city of Milan because it could not cope with the backlog building up at Britain's main air hub.

BA announced the delay to the long-haul switch in a joint statement with the airport operator BAA. The two companies said that a normal flight service had operated at T5 since Tuesday but they wanted to ensure that customers could be confident of high service standards when additional flights were introduced.

The flights out of Terminal 4 represent one-quarter of BA landings and departures, but account for 50 per cent of customers. They were to have been moved to Terminal 5 by April 30.

“We will work together to iron out any remaining problems, including the baggage system and its operation, and develop a robust timescale for phasing the move of Terminal 4 services into Terminal 5,” today's statement said.

Willie Walsh, the BA chief executive, said: “We are making this decision in the interests of customers. Though Terminal 5 is now working well, we need to have confidence that good service can be maintained when the terminal is handling larger numbers of customers.

“It is only sensible to ensure that Terminal 5 is operating consistently at a high standard before the move begins.”

Colin Matthews, BAA’s chief executive, said: “BAA regrets this postponement, and we recognize the impact it has on other airlines, but we believe it is a wise precaution to ensure that passengers can have the maximum confidence once the move does take place.

“We will be working very closely with BA in the intervening period to ensure that result, as well as working with the other airlines to mitigate as much as possible the knock-on effects.”

“BAA fully recognises that the inauguration of Terminal Five has not been as smooth as we and BA would have wished. In the last few days passengers have seen significant improvement and our goal is to complete that process as soon as possible before continuing the next phase of transforming the rest of the airport.”

So far Terminal 5 is handling UK domestic flights, all European flights apart from Barcelona, Madrid, Lisbon, Nice and Helsinki, and services to Johannesburg, Hong Kong, Los Angeles, Miami, San Francisco, Tokyo, Tripoli and Vancouver. Those operations will not be affected.

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