Thousands of Irish passengers are suffering holiday hell after missing flights and queuing for up to four hours due to tough new security checks introduced in the wake of terror attacks.

Chaos has erupted at airports in Spain, Portugal, France, Italy, and Belgium due to EU border controls implemented after the Paris and Brussels attacks.

Some tourists are being hit by airport delays which go on for longer than their flights.

Irish passengers face delays abroad because their details must be run through new databases at passport control booths at airports and sea ports, to see if they pose a threat.

The rules mean passengers have to have their passports checked against databases including the Schengen Information System and an Interpol database on stolen and lost travel documents.

A group representing airlines including Ryanair, easyJet and IAG, Airlines for Europe, said some people were in queues for up to four hours.

The problem is being blamed on the introduction of tighter EU-introduced border controls in Schengen, the border-free area that incorporates most EU member states.

Previously, Irish and British travellers have been given only visual passport checks by European border officials.

But the new rules mean checks against a series of databases are now carried out on each passenger from non-Schengen countries.

Ryanair has told customers to arrive at least three hours before scheduled departure, but last night said operations across its network are running as normal.

Meanwhile, a pilots union claimed that those travelling through Dublin Airport have been plagued by bottlenecks due to infrastructural problems.

The union has apologised to the public for alleged delays at Dublin Airport and claimed the shopping mall is more important to management than its runways.

President of the Irish Airline Pilots' Association Evan Cullen said inadequate infrastructure at the airport is causing major bottlenecks.

"The Dublin Airport Authority considers its shopping mall to be more important and has little or no regard for the inconvenient runway that's taking up its car park space," he said.

But a spokesman for Dublin Airport hit back at the claims, which he said are not supported by the facts.

The spokesman said Dublin Airport's 'on time' performance for departing flights in June was 10pc better than the same month last year.

He said it was "rather ironic" that IALPA was voicing concerns about infrastructural issues given that it lodged planning objections to two Dublin Airport infrastructure projects.

These were subsequently approved by the planning authorities, he said.

He said Dublin Airport is currently investing €100m a year to upgrade and maintain its facilities for the benefit of airlines and passengers.

Separately, industrial action at a Barcelona Airport has inflicted further misery.

Staff at El Prat airport added to weary travellers' stress levels when they deliberately took the maximum of 10 minutes to pass each passenger through security during a work-to-rule.

The industrial action during peak holiday season caused around 1,000 people to miss flights at the airport in the past few days, airline bosses said.

Hour-long strikes are expected to begin on Friday at Spain's busiest airport.

Have you been affected by the airport delays? You can contact us on email at contact@independent.ie or by phone to 01-7055801

Irish Independent