The threat of widespread disruption to air passengers over St Patrick's weekend has been averted after the High Court ruled a stoppage on Friday cannot go ahead.

The court granted an injunction to the Dublin Airport Authority restraining SIPTU from holding a four-hour work stoppage at Dublin and Cork airports.

The union had served notice of industrial action at Dublin, Cork and Shannon airports in a dispute over pensions.

The move has been welcomed by the DAA and Ryanair.

Aer Lingus said the damage had already been done and a cloud of uncertainty created by the strike threat had disrupted thousands of customers.

The airline said changes have already been made to its schedule and the effect of the planned strike could not be undone with less than 36 hours to go.

Aer Lingus said it was yet another occasion where a trade union had cynically caused damage by threatening a strike only to withdraw their strike notice at the last minute.

SIPTU has confirmed Friday's action will not go ahead.

The trade union added that any possible peaceful protests have nothing to do with it.

The DAA called on SIPTU to engage with an expert panel established last week to seek a resolution to the pension issue.

Minister for Transport Leo Varadkar also welcomed the ruling by Mr Justice Paul Gilligan.

He said: "I have said on a number of occasions that the strike should have been deferred given that the expert panel is currently engaging with all parties involved in the dispute."

Mr Justice Gilligan ruled that there was a fair question to be tried in relation to the validity of SIPTU's ballot and whether the union should have restricted the ballot to its members who belonged to the aviation pension scheme.

He also said there was a fair question to be tried in relation to whether key personnel, including security staff who had separate agreements, could be involved in industrial action before certain procedures had been exhausted.

Mr Justice Gilligan noted on a number of occasions that SIPTU had not provided replying affidavits to contradict the submissions of the DAA and Ryanair.

He granted the injunction sought by the DAA and urged the parties to cooperate with the expert panel to resolve the dispute.

Yesterday, the DAA told the court that it would suffer catastrophic and irreparable damage, as well as millions of euro in losses, if the action went ahead.

But SIPTU defended its entitlement to take strike action.