"Especially during the peak season of the year, travellers face long lines and can't get on their flights".
Passenger figures are up 4 per cent over the same weekend previous year, with over 2,669 flights expected to arrive and depart between Friday and Monday.
Some airports are already reporting delays of up to three to four hours at some airports, including Milan, Palma de Mallorca, Madrid, Lisbon, Lyon, Milan, Paris-Orly and others.
Airlines For Europe (A4E) managing director Thomas Reynaert said: "Travellers face long lines and can't get on their flights".
According to BBC News, this process is taking two minutes longer per passenger.
Ministers were forced to intervene over the crisis at European airports yesterday as it emerged that airlines were being forced to delay flights because of lengthy queues at passport control.
People are being warned to check what terminal they are flying from, arrive in plenty of time for their flights and to expect large crowds in the airport.
"It is also extremely important that border control check points are sufficiently resourced so that queuing times are kept to a minimum".
Aceta, the association of Spanish air transport companies, said some airlines had to delay flights because many of their passengers could not board on time.
The Schengen area consists of 26 nations, including 22 of the 28 European Union members (excluding the UK, Ireland, Bulgaria, Romania, Cyprus and Croatia), along with non-EU members Norway, Switzerland, Iceland and Liechtenstein.
The delays are reportedly being caused by the introduction of newly-toughened and more time consuming immigration checks.
Airports in Europe have been given six months, ending in October, to enhance security following a string of terror attacks in the region.
"Every member state agreed to them, so the rules we have are very clearly there to protect the security of our citizens".
"We will be busy this weekend but are not experiencing heavy congestion.and we will have the extra customer care staff in place", a spokesman for the DAA said.
Staff at El Prat airport added to tired travellers' stress levels when they deliberately took the maximum of 10 minutes to pass each passenger through security during a work-to-rule.