Foreign magistrates who are not Irish or Commonwealth citizens have been barred from the bench with immediate effect.

The decision was made by the Lord Chancellor following the discovery of a long-forgotten 300-year-old law banning the appointment of foreigners to the post.

Successive governments have allowed the practice to continue for years and it is believed the number of individuals affected runs into three figures.

A spokesman for the Lord Chancellor's Department said Lord Irvine's order would not affect the running of the courts and decisions made by the magistrates involved would stand.

Oath of allegiance

"It has been the very long established practice, going back over many governments, that a nationality requirement has not been applied to lay magistrates," the spokesman said.

"It has now come to light that a section of the Act of Settlement of 1701 limits those who may hold office under the Crown to citizens of the UK, Irish Republic or the Commonwealth.

"We are now looking at how to regularise the position for the very few individuals who are affected."

Across England and Wales there are more than 26,000 magistrates.

Foreign citizens who are established members of their community have been allowed to sit after taking an oath of allegiance.