Activist investor Elliott Investment Management today escalated its boardroom battle with Southwest Airlines, saying it plans to request a special shareholder meeting as soon as next week to overhaul the airline’s leadership.

The U.S. carrier, however, once again ruled out any leadership change, saying CEO Bob Jordan was the “right leader” to successfully execute its strategy to improve financial performance and drive shareholder value.

The hedge fund has launched a campaign to oust Jordan and other top executives, blaming them for the company’s underperformance. It wants Southwest to change the way it runs its business and has laid out plans to replace two-thirds of the board’s 15 directors.

Elliott owns more than 10% of Southwest stock, enough for it to call a special meeting.

The hedge fund shared its plan ahead of the airline’s investor day on Thursday, where Jordan is expected to outline a turnaround strategy.

In response, Southwest said its board would review the request for a special shareholder meeting, but accused the hedge fund of trying to disrupt its investor day.

The Dallas-based airline has struggled to find its footing after the pandemic, in part due to Boeing’s aircraft delivery delays and industry-wide overcapacity in the domestic market.

Its operating margin declined to 0.2% in the first half of this year from more than 13% in 2019. In comparison, Delta Air Lines posted an operating margin of 9.5% in the first six months, with United Airlines at 7.4%.

Southwest’s shares have lost about 43% in the past three years, compared with a 9% gain in Delta’s shares.

To turn around its fortunes, Southwest plans to offer assigned and extra-legroom seats to attract premium travelers, and start overnight flights. The company also intends to carry out network changes, and has said it would share more details on Thursday.

“Any leadership change amid such a significant transformation would be detrimental to all shareholders,” Southwest said late today.

In a bid to prevent a proxy fight, the company this month said six directors would step down in November and Executive Chairman Gary Kelly would retire next year.

Southwest would appoint four new independent directors in the near future and would potentially include up to three candidates proposed by Elliott, it said at the time.

In a letter to shareholders today, Elliott accused the airline of obstructing a leadership change.

“We do not support the company’s current course, which is being charted in a haphazard manner by a group of executives in full self-preservation mode,” it said.

“The urgency of management and board change at Southwest could not be clearer.”

Today, Southwest said while its shareholders want it to seek a compromise with Elliott, “acquiescing to a single shareholder’s demand for absolute control of the company is not a compromise.”

Southwest’s last annual shareholder meeting was in May. The next meeting is not scheduled until next spring.