Figures from Revenue show €9 million was collected in June from the air travel tax compared with €11.5m in the same month last year.

The Government announced the introduction of the travel tax in 2008 and  said at the time that it expected to raise €150m in a full year. It later revised that downward to €125m.

However, in the first six months of this year the take is almost €45m, which would indicate that it is behind target. Last year’s take was €84.4m for eight months.

Ryanair has constantly demanded that the Government abolish the departure tax saying that if it did the airline would add more routes in Ireland.

Airline analysts, anna.aero, recently blamed the Government’s €10 travel tax for Dublin emerging as the worst airport in Europe in an analysis of seat capacity.

It said that for the summer 2010 season airline seat capacity in Europe rose by almost 5% but capacity in Dublin is expected to fall by 9%, making it the worst performer among the 20 European airports surveyed.

Bloxham stockbrokers’ analyst, Joe Gill, estimates the tax could cost the economy around €450 million a year as tourists will stop coming to Ireland.

The travel tax came into effect at the end of March 2009, resulting in every person leaving Ireland travelling over a certain distance being charged  an extra €10 per flight.

Mr Gill said the tax was 'regressive and ignorant of seasonal trends in air travel demand'.

As well as Ryanair, Aer Lingus and CityJet have also called for the scrapping of the tax.