(Reuters) - Activist investor Elliott Investment Management on Tuesday escalated its boardroom battle with Southwest Airlines ( LUV ), saying it plans to call a special shareholder meeting as soon as next week to overhaul the airline's leadership.

In a letter to shareholders, the hedge fund accused the airline of obstructing a leadership change.

Elliott now owns enough Southwest ( LUV ) stock to call a special meeting and take the next steps to shake up the board and management. In August, it identified 10 director candidates it could nominate to the 15-member board.

Southwest ( LUV ) did not immediately respond to a request for comments.

The airline this month said it would appoint four new independent directors in the near future and would potentially include up to three candidates proposed by Elliott.

However, the company expressed confidence in CEO Bob Jordan, saying there was "no better leader" to successfully execute its strategy to "evolve the airline and enhance sustainable shareholder value."

Southwest ( LUV ) has been struggling to find its footing after the pandemic, in part due to Boeing's aircraft delivery delays and industry-wide overcapacity in the domestic market.

It plans to offer assigned and extra-legroom seats to attract premium travelers, and start overnight flights. It will present details to investors on Sept. 26.