Worst-hit was thought to be Glasgow, where 1,000 passengers were stranded waiting to board holiday flights as the Spanish ended their strike, but then began a work-to-rule.

BBC reporter Karen Bowerman: the backlog is clearing

Passengers were asked to check in as normal - but were warned they could be delayed between two and nine hours.

A delayed flight to Ibiza finally departed at 0830 after being delayed for nine hours.

At Manchester Airport, more than 2,000 people were forced to spend Friday night camped down. One flight was held up by 14 hours.

At Gatwick, there was an average delay of up to three hours on flights to Spain or to destinations such as the USA or Portugal with routes through Spanish airspace.

Steven Gargaro, Glasgow Airport duty manager, said: "Several operators have taken passengers away from the airport terminal, but some the passengers are remaining around the building. Most people are being understanding."

BAA at Glasgow said the dispute also affected homeward-bound holidaymakers.