The chief executive of British Airways has asked employees of the troubled airline to take an unpaid leave or work without pay for a month to help the firm recover financially.

BA boss Willie Walsh said he and chief financial officer Keith Williams will be working unpaid for a month and urged 40,000 staff nationwide via e-mail and the firm's in-house newspaper to emulate them, the airline's spokeswoman Kirsten Millard said on Tuesday, according to Yahoo! Finance.

An official of the airline's union, however, said the proposal is not practical.

"It's all well and good for Willie Walsh to say he's prepared to work for free when he earns four times in a month what they do in a year," Ciaran Naidoo, a spokesman for Unite, told Yahoo! Finance.

British Airways is struggling financially after losing $655 million in May,