LONDON (Reuters) - Ryanair faced growing criticism from unions and investors on Friday about how it has handled an industrial relations revolt ahead of its annual shareholder meeting next week when its veteran chairman’s position will be challenged.

A Ryanair aircraft stands on the tarmac at Frankfurt-Hahn Airport during a strike of their pilots and cabin crew in Hahn, near Frankfurt, Germany, September 12, 2018. REUTERS/Ralph Orlowski

Britain’s Local Authority Pension Fund Forum (LAPFF) recommended members vote against Ryanair’s financial report at the Sept. 20 meeting and also oppose the re-election of Chairman David Bonderman.

The group, whose members schemes run around 230 billion pounds ($300 billion) on behalf of teachers, cleaning staff and other public workers, said its recommendations reflected “significant concerns” about Ryanair’s treatment of workers.

Ryanair has struggled with labor relations in recent months and endured its worst one-day strike last month, disrupting the plans of an estimated 55,000 travelers. Another one-day strike by cabin crew is planned across five countries on Sept. 28.

“Ryanair has failed to adequately address concerns about the company’s troubled relationship with its employees and the potential impact on its business,” LAPFF Chair Ian Greenwood said in a statement.

“The company faces more strikes and allegations of poor working conditions continue to emerge. Questions about the company’s business model and governance now pose a threat to shareholder value.”

Ryanair praised Bonderman in a statement as an “outstanding” chairman and predicted that “shareholders will pass all AGM resolutions by a large majority this year.”

A day after Ryanair’s received a boost by signing collective labor agreements with three unions in Italy, one of its major markets, it faced the prospect of the industrial strife spreading to Poland, one of its fastest growing markets.

Ryanair refused to accept the registration papers of a newly formed Polish union and threatened workers with redundancy if they did not accept self-employment contracts with its Polish subsidiary, Ryanair Sun, by September 30, the International Transport Workers’ Federation (ITF) said in a statement.

A spokesman for Ryanair said that the ITF claims were false but declined to specifically respond to each one when asked to do so.

Britain’s LAPFF said that Bonderman had been in the role too long and there were “significant doubts” about his independence. Bonderman has been in the job since 1996.

It could not immediately confirm how large a stake its members hold in the airline.

Bonderman also faces opposition to his reappointment from proxy-advisory firm Glass Lewis & Co and the ITF.

“Ryanair’s employment issues highlight long-standing concerns about governance and in particular Mr Bonderman’s oversight role as chair of the board and his ability to influence the CEO, Michael O’Leary,” Greenwood said.

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