EasyJet Deputy Chairman and Senior Independent Director David Michels will step down from the low-cost carrier’s board—but not soon enough to satisfy founder and largest shareholder Stelios Haji-Ioannou, who has become a thorn in the side of the airline’s leadership since he quit the board last year.

EasyJet announced May 23 that Michels decided to step down following the end of his second three-year term at the end of this year. The airline says it has started the process of recruiting his successor.

“On behalf of the EasyJet board, I would like to thank David for his work as a board member over the past five years, including his time as chairman of the board from July to December 2009,” EasyJet Chairman Michael Rake said. “David has made a very valuable contribution to the development of EasyJet.”

But Haji-Ioannou blasted out an e-mail with a different view. Haji-Ioannou quit last year because he believed the leadership was discounting his view and focusing more on growth than profitability; he vowed to become an activist shareholder to try to block the expansion plans. He has become the leadership’s most vocal critic, and he did not let up in this statement.

Michels is doing “the right thing” by leaving, he said in the statement but added, “I cannot see the benefits of Sir David staying on for an additional six months, given the fact that he has no long-term links with the company. It is my view that board members who have ‘checked out’ of a company should not be involved in long-term strategic decisions such as aircraft purchases.”

He cited a list of what he considers dubious results since Michels joined the board: a 10% decline in share price; the absence of dividends to shareholders; the board-approved acquisition of 94 Airbus aircraft at an “exorbitant” cost; and the board’s early January approval of the purchase of 15 more Airbus aircraft, about two weeks before the company issued a profit warning.

“Sir David should have, following investigation, foreseen the profit warning” issued on Jan. 4 “and not ordered the 15 aircraft,” he added.