A total of 450 court cases brought by citizenship applicants were lost or settled over the period, many of which likely relate to delays in processing applications, the Business Post reports.

The €4.5 million sum was paid out in legal costs to 47 different law firms and organisations.

Immigration lawyers said most of the settlements likely related to processing delays, with the average processing time having increased from seven months in 2017 to 19 months in 2022.

The Department of Justice said the citizenship process is “still largely paper-based” and backlogs had been created by the pandemic as well as a significant 2019 ruling on citizenship law.

The High Court’s ruling in Jones v Minister for Justice and Equality [2019] IEHC 519 — later successfully appealed to the Court of Appeal — led to the loss of six months’ processing time.

In June, the State formally adopted a set of litigation principles which include minimising legal costs for all parties and making appropriate settlement offers.