Holidaymakers hoping to squeeze maximum time in the sun during the school half-term week lost their first day as airport officials tried to clear the queues. Normal service was not resumed until last night.
The knock-on impact of the power failure, which affected Terminals 3 and 4 on Friday, meant many passengers had to sleep rough in the lounges and wait until yesterday to get away. Check-in desks were besieged. Departures from Terminals 1 and 2 were also delayed by refuelling difficulties.
Passengers landing had to wait for up to three hours to collect their luggage and leave the airport. A Heathrow spokesman said: 'It was a pretty busy day here anyway, as the Bank Holiday weekend and the school half-term holidays began.'
The holidaymakers - among an estimated 1.5 million people leaving for sunny destinations abroad - left behind what forecasters described as patchy weather in Britain. Scotland and Northern Ireland were expected to enjoy the best of a mediocre weekend.
The Meteorological Office said much of the country would be overcast and that hotspots, with temperatures of up to 21 degrees Centigrade today, would be 'close', with a risk of thunderstorms.
Stephen Davenport, senior forecaster at the Press Association WeatherCentre in London, said: 'If you're having a barbecue, it would be an idea to keep an eye on the forecasts in your area, but otherwise it should be a pleasant Bank Holiday.'
On the roads sports events - including England's World Cup cricket clash against India at Edgbaston - as well as air shows and local festivals threatened traffic jams.
