Operators of new routes from Dublin, Cork and Shannon airports would get a 75 per cent discount on charges in the first year and a 50 per cent one in the second year in a scheme proposed by Aer Rianta.

The scheme, which must receive approval from the Minister for Public Enterprise, Ms O'Rourke, would replace the rebate scheme which will be phased out completely by 2004. Aer Rianta will also apply to the minister to make Dublin a scheduled airport.

Mr Hanlon, the chairman of Aer Rianta, challenged the chief executive of Ryanair, Mr Michael O'Leary, to come forward with "ten new routes" after announcing details of the discount scheme. Mr Michael O'Leary said last night that his airline did not care about Dublin if it persisted in its charges, which were a substitute for loss of duty free.

Mr Hanlon said Aer Rianta's airport charges had not increased since 1987 and "despite the comments of some people" continued to be the lowest in Europe.

The group gets 16 per cent of its revenue comes from airport charges, compared to similar airports which get up to 50 per cent.