LONDON, May 28 (Reuters) - British Airways plans to fly all long haul services from Heathrow on Sunday, but due to overcrowding passengers will not be admitted to the airport terminal until 90 minutes before their flight, chief executive Alex Cruz said.

In a video statement posted on Twitter, Cruz said due to the knock-on impact of disruptions on Saturday caused by a global computer system failure, there would be delays and some short haul flights would be cancelled from Heathrow.

He also asked passengers not to turn up to Heathrow too early.

"Because of the numbers of people here customers are not being admitted into Terminal 5 until 90 minutes before their flight's scheduled departure," he said, adding that passengers who decided not to fly would be able to rebook for dates until the end of November or receive a full refund.

(Reporting by Kylie MacLellan; Editing by Alison Williams) ((kylie.maclellan@thomsonreuters.com; +44 207 542 0401; Reuters Messaging: kylie.maclellan.thomsonreuters.com@reuters.net))

Keywords: BRITAIN AIRPORTS/BRITISHAIRWAYS CRUZ