Deportation of illegal immigrants costs in some cases up to €30,000 for each person. However, the Minister for Justice insisted he would not be "browbeaten" into abandoning "enforcement of the law" through deportation, otherwise "our system will simply implode".

Mr McDowell said people could get the message from the Government that "you aren't deported if you kick up a fuss". Any credibility the system had depended on "the willingness of the State to enforce the laws of the land".

The average cost of each deportation was €3,000 but in one instance, deporting six Nigerians using a charter flight cost €190,000. In the past two years 849 people had been deported at a cost of €2.859 million, Mr McDowell told the Dáil during justice questions.

Labour's justice spokesman, Mr Joe Costello said using charter aircraft to deport people was not cost-effective. The Minister might as well send people on a "pleasure cruise" because of the price. He suggested that the Government jet should be used for deportations.

Mr McDowell said an average cost of €3,000 for each deportation was not vastly inflated given the cost of scheduled flights to Nigeria. Deportation costs this year included three charter flights, one to Algeria in January and two to Nigeria. Six Nigerians were deported in March on a charter flight which cost €190,000, with 20 escorting gardaí whose costs were €7,671.

A further 12 were deported on November 14th at a cost of €151,500 with 35 escorting gardaí whose costs amounted to €14,361. In January the deportation of two Algerians on a charter flight cost €23,000, with five escorting gardaí whose costs were € 714.

Mr Costello asked whether using gardaí for escort duty was the best use of Garda resources. Mr McDowell said in future it might be possible to use non-Garda security staff to enforce order on aircraft. He said charter flights were the only viable option in certain cases because of the disruptive behaviour of those being deported or for passenger safety concerns.