U.K. flights operated by Ryanair Holdings Plc have been taking off largely as scheduled after pilots in the discount carrier’s biggest market began a two-day strike ahead of the busiest weekend for travel this year.

All services departed as scheduled Thursday morning, with some delays due to air-traffic congestion, Ryanair said in an email. Data from aircraft-tracking website FlightRadar24 showed flights at London Stansted, the carrier’s biggest base, operating normally.

The walkout by members of the British Airline Pilots’ Association started at midnight after Ryanair failed to block it with a legal injunction. The union said in a Twitter post that the protest over pay and conditions is aimed at “making Ryanair a better place to work,” without commenting on its effectiveness.

Europe’s biggest low-cost airline is slated to carry 259,000 people on more than 1,700 U.K. flights over the 48 hours of the strike, according to aviation-data provider Cirium. Annual travel peaks on Friday as Britons get away for the long weekend that extends through Monday, the last bank holiday of summer.

Ryanair said via Twitter that it expects to operate a full schedule through the action, while not ruling out some delays or flight changes. The Dublin-based company has said that Balpa represents a minority of its U.K. pilots.

Irish Decision

The union said after the court ruling that it was prepared to suspend the walkout if Ryanair agreed to a framework for further negotiations, before adding that the overture had been rejected. The labor group is planning a further two-day walkout in September.

The London High Court decision contrasted with an earlier one in Ryanair’s home market of Ireland, which barred pilots there from walking out.

Chief Executive Officer Michael O’Leary upped the ante in the labor clashes last month when he told pilots and flight attendants that hundreds of jobs must go and bases close to cope with a possible no-deal Brexit and slower growth after the grounding of Boeing Co.’s 737 Max jet.

Cabin crew at Ryanair’s Spanish bases have threatened to strike next month over plans to close three locations unless unions agree terms. Staff in Portugal are in the midst of a five-day action over holiday allowances and dues.