The Northern Ireland police service’s controversial 50:50 recruitment scheme has been extended for another three years as the force struggles to meet its goal of increased Catholic representation.

The decision has come under fierce attack from Ulster Unionist politicians, who believe it wrongly excludes Protestant applicants and costs too much to implement.

Failed applicants are being aided by Unionist peer Lord Laird of Artigarvan in a bid to take their case to the European Court of Justice.

The scheme is administered by Consensia, a consortium owned by professional services firm Deloitte, advertising agency AV Brown, HR consultant Pearn Kandola and BMI Health Services.

Successful applicants go into a recruitment pool, from which appointments are made on a 50% Catholic, 50% non-Catholic basis. Applicants who make the pool but not the quota must start again.

Consensia is currently gearing up for its seventh recruitment drive. But while the first campaign brought a flood of applicants, response has recently fallen off, leading to a shortage of Catholic applicants and, consequently, more disappointed non-Catholics.

A further problem, which has been highlighted by a spate of racial attacks in the province, is that the policy hinders the recruitment of ethnic minorities, who tend to fall into the “non-Protestant” category.