A spokesperson for the Home Office said the adverts “should instead have read ‘a full and valid passport’”, and added: “We apologise for this error and are now in the process of correcting it.”

The Equality Commission for Northern Ireland (ECNI) was among organisations which raised concerns with the Home Office.

Eileen Lavery, head of advice and compliance, said: “We have pointed out that this could raise concerns about possible discrimination on grounds covered by the Fair Employment and Treatment Order, which includes political opinion, and/or by the Race Relations Order.

“We also suggested that, in determining who qualifies as eligible for the posts, and in deciding what documents will be required as proof of that, the Border Force should give consideration to Article 1(vi) of the Belfast/Good Friday Agreement, which recognises the right of all the people of Northern Ireland to identify themselves and be accepted as Irish or British, or both.

“The Agreement also confirms that their right to hold both British and Irish citizenship is accepted by both Governments.”