Open warfare broke out at easyJet today as director, founder and 41% shareholder Stelios Haji-Ioannou refused to sign off the company's accounts.

In an extraordinary escalation of hostilities, the entrepreneur raised serious accounting issues at the company in his campaign to get more of his placemen on the airline's board, cut expansion by reining in the delivery of 85 new aircraft and force easyJet to start paying him dividends.

His latest outburst sent the shares to new lows, off 27¼p at 249¼p. In a statement to his fellow directors, Stelios said: "I am unable to approve the annual accounts [because] I am concerned about the application of certain of the accounting policies adopted by the board in a way that I believe is at odds with current commercial realities and the macro-economic climate."

The issues arise out of easyJet's acquisition of GB Airways, and cover the valuation and impairment of routes, Gatwick landing slots and GB Airways aircraft. Stelios compared easyJet's accounting policies unfavourably with those of arch-rival Ryanair.

However, the raising of the accounting issues was seen as a front to up the pressure on the easyJet board to conserve cash and start paying dividends, having previously eschewed them in favour of investing for growth.

Of the accounting policies, easyJet chief executive Andy Harrison said: "These issues have been extensively debated by the board, its audit committee and with our auditors PricewaterhouseCoopers."

Of Stelios's intervention over easyJet's strategy, Harrison said: "It is not ideal. Stelios has a very bearish view of the economy which he is entitled to."

EasyJet reported a 45% collapse in profits to £110 million in the year to the end of September.