A maintenance company from which Ryanair rented hangar space at Dublin airport "colluded" with Dublin Airport Authority (DAA) in favour of Aer Lingus to deny the budget airline longer-term accommodation, the High Court in London was told yesterday.

Ryanair is asking the London High Court to compel SR Technics - by the remedy of "specific performance" - to honour promises it says were made by the maintenance company in 2000 in side letters to contracts to seek a 15-year licence to use Dublin airport hangars in return for moving its maintenance operation from Stansted.

The company originally provided maintenance services for Ryanair, but despite the expiry of its contract - and Ryanair using other companies for maintenance - the airline is seeking to bind the maintenance company to what it says was an original agreement to secure Dublin airport hangar space for 15 years entered into when it still provided services.

Ryanair is due to quit the hangars it rented from SRT the first week in January and is seeking to reverse the termination notice.

Both the DAA and SR Technics were yesterday openly accused of "lying", dissembling and collaborating on their evidence to the court in London, by counsel for Ryanair, Hannah Brown.

SR Technics, also known as SRT, not only failed to use its "best endeavours" to secure the hangar licences from DAA as obliged, it deliberately prevaricated so that it would continue to get rental income from Ryanair while ultimately leaving itself free to surrender its own hangar agreement to DAA for allocation to Aer Lingus and in return for €3.39 million, Ms Brown told Mr Justice Gray.

She produced correspondence as evidence of agreement between Ryanair's director of engineering Michael Hickey and the SR Technics's then chief executive Declan O'Shea that his company would make hanger space available for a single 737-800 jet at Dublin airport.

Ryanair, in turn, honoured its promise to pay £1,071,595 to SR Technics, she said.

Ms Brown accused Declan O'Shea of lying to the court earlier this week in his evidence when he said the hangar arrangement with Ryanair had been a temporary "ad hoc" arrangement and never a long-term commitment.

Mr Justice Gray is expected to rule next week.