Ryanair last night rejected accusations made by Aer Lingus's staff shareholding group that the offer document it issued this week contained inaccurate claims.

In a letter to the directors of the Employee Share Ownership Trust, Ryanair's chief executive Michael O'Leary confirmed that employees of the former State airline stand to benefit by more than €220 million if the rival carrier's offer is accepted. He reiterated that this equates to more than €60,000 for each of Aer Lingus's 3,200 employees.

Mr O'Leary's letter was written in response to accusations by the Esot on Thursday that Ryanair's document contained inaccuracies. The Esot wrote to the Takeover Panel to complain that the €60,000 calculation was misleading, indicating that the correct figure was €38,864 per member.

This lower figure was arrived at by deducting the Esot's borrowings of €35 million, and what Mr O'Leary described in his letter as an "unexplained deduction of over €6 million".

Ryanair said last night that its calculations were "factually correct", but has requested clarification from the Esot on the exactnumber of current and past members of the trust, and details of how the proceeds of Ryanair's offer would be distributed among these members.

"This clarification will allow any confusion over the proceeds of Ryanair's offer to be removed," Mr O'Leary said in the letter.

Aer Lingus itself placed the value of the offer at just €32,500 per Esot member. "The numerous misrepresentations by Ryanair will be dealt with in full when Aer Lingus issues its response to Ryanair's conditional offer," the airline said.

Aer Lingus questioned Ryanair's claim that Esot members would be able to receive entitlements on a tax-free basis, describing it as "highly conditional, dependent on Revenue approval, and, extraordinarily, dependent on Aer Lingus employees and former employees going into the public market and buying shares in Ryanair".