Ryanair Holdings Plc pilots in the U.K. will walk out for an additional seven days, after five days of strikes failed to bring the discount airline back to the bargaining table.

Pilots represented by the British Airline Pilots’ Association will stay away for seven days scattered over the second half of this month, the union said Wednesday in a statement.

A walkout ahead summer’s busiest weekend, and a second round of actions that end tonight, have failed to disrupt service. The union said it’s nevertheless forced Ryanair to pay for contractors and bring in foreign crews, and it’s “been left with no choice” than to keep up the pressure. It accused the discount airline of “intransigence,” and said its demands, centered around issues like pensions, insurance, and maternity benefits, “are not unreasonable.”

“Ryanair should stop dragging its feet and get back to the negotiating table,” Balpa General Secretary Brian Strutton said in the email.

Ryanair said the union’s latest move was “pointless” as the previous strikes “operated as scheduled with zero cancellations.” The carrier said that the union should return to talks as “these failed strikes have not achieved anything.”

The new strike dates are: Sept. 18-19, Sept. 21, Sept. 23, Sept. 25, Sept. 27 and Sept. 29, the union said.

The pilots previously struck work on Aug. 22 and 23, ahead of the U.K.’s busiest travel weekend. But the action failed as Ryanair’s flights operated as scheduled. That was followed by an additional three days this week.

Europe’s biggest carrier has grappled with strikes and deteriorating labor relations over recent years. Chief Executive Officer Michael O’Leary has announced hundreds of job cuts and the closing of bases to cope with a possible no-deal Brexit and slower growth after the grounding of Boeing Co.’s 737 Max. Last month, the carrier told employees that it would close four bases in Spain, affecting as many as 512 cabin crew and pilots.