Ryanair Holdings Plc was sued by a package holiday service over accusations that the airline is exploiting its market dominance in an “aggressive” pursuit against online travel agents.

On the Beach Group Plc accused the budget airline of monopolizing the market for booking services and not giving customers a “free and fair choice,” according to a London court filing.

A Ryanair spokesperson didn’t immediately respond to a request for comment. The airline is yet to file a defense to the claim.

“Ryanair wants, and has for some years, been aggressively seeking to eliminate competition from On the Beach—and other online travel agents—in the U.K. and throughout the EU,” the company’s lawyers said in the lawsuit filed at the U.K. High Court earlier this month.

The holiday booking agency alleged the airline of a “smear campaign” against it and other booking sites by blocking payments, preventing customers from managing bookings, and degrading customers’ experience, the lawyers said.

The case is part of a long-running dispute between Ryanair and companies that it calls “screen-scrapers.”

Ryanair hit out at On the Beach and other similar companies last year for allegedly blocking refunds for Covid-19 flight cancellations.

A spokesperson from On the Beach declined to comment.