Holidaymakers have been told to arrive at airports at least three hours before their flight because of chaos caused by new EU passport controls.

Queues of up to four hours have been reported since tightened security checks were introduced.

Airports in Spain, Portugal, France, Italy and Belgium have been affected.

Some airports, such as Majorca, are predicted to experience double their usual demand.

This weekend is predicted to be one of the busiest of the year with 10 million passing through European airports on Saturday and Sunday.

BA, easyJet and Ryanair have told passengers to turn up earlier than usual.

BA is sending text messages to passengers flying back from airports where long lines at border controls are expected.

A spokeswoman said: "We're texting customers flying from airports that we know are having issues to ask them to arrive early."

The carrier has promised that any customers who miss their flight because of the queues will be re-booked for free.

EasyJet told passengers it strongly recommended they allow extra time at airports "to be able to get to the gate on time".

It advised customers to check the latest travel information on its **website**and that if any flights were particularly affected they would alert passengers via their Flight Tracker tool or text message.

Ryanair issued an alert which urged its customers to arrive "at least three hours before the scheduled departure time".

New European Union rules were introduced following the terror attacks in Paris and Brussels.

They require countries to carry out more stringent checks on travellers entering and leaving the Schengen area, which allows passport-free movement across much of the EU.

This has led to long lines at border controls as the details of passengers from non-Schengen countries - such as the UK - are run through databases to alert authorities if they are known to pose a threat.

Some passengers have reportedly missed their flights because the delays are so long.

Lobby Group Airlines For Europe (A4E) warned the situation could worsen in the coming weeks as the new regulations have not yet been fully implemented.

The six-month period to put the enhanced checks in place ends on October 7.

The Government has been urged to "use whatever influence it can" to pressure EU states to speed up the process.

It follows reports no extra staff have been put on to cover the extra checks.

Tourists arriving in some popular destinations have been met with "shameful" immigration lines hundreds of metres long, one lobby group said.

Airlines UK, an industry body representing UK-registered carriers, said it warned the Department for Transport (DfT) about the problem in May, but were told by ministers the issue had eased.

Ryanair boss Michael O'Leary said earlier this week that more than a fifth of the airline's flights were delayed because of the issue and he is "jumping up and down" in frustration.

Just 78% of the Dublin-based carrier's flights were on time on Tuesday, down from 90% during the month of August as a whole last year.

He told a central London press conference he could not understand why passengers on outbound flights were being checked, saying: "If people are leaving your country, what the hell is the problem?"

Aviation minister Lord Callanan has said he will urge his counterparts in Portugal, Spain and Italy to "do all they can to reduce queues and allow travellers to get on with their holidays".

EU commissioner for security Julian King said checking travellers against the EU-wide counter-terrorism and law enforcement databases - which have more than 8,000 terrorists listed - helps to "keep us all safer and more secure".

He added the system was proposed in 2015 and agreed last year, so authorities have had "lots of time to prepare and put in place the necessary arrangements".