The descendant of a martyred saint has been barred from his local faith school for not being Catholic enough.

Alexander Payne's Catholic ancestry stretches back more than 900 years and includes Saint John Almond, who was hung, drawn and quartered in 1612 by Protestant persecutors.

But the five-year-old, of Cornwall Gardens, Brighton, has been told he will not be allowed to join friends at St Bernadette's School in nearby Preston Road because he was baptised after the age of two.

His father, telecoms worker Chris Payne, has vowed to sue the school.

He said: "My son is at the end of a long line of Catholics that can be traced back to 1092.

"Between that time and this, his ancestors maintained their Catholic faith, with many suffering during the Reformation.

"The school continues to maintain it has introduced this rule to limit the number of children admitted whose parents only had them baptised to get them into the school.

"This means that despite living right next to the school and regularly attending mass in the parish for eight years, I have to take my son to a Catholic school on the other side of town."

Mr Payne has tried and failed to get the ombudsman to force a rethink from the school's governors.

He said: "My son is now effectively classified as second-class and recently had this confirmed to him outside church.

"One child said to another, 'This is my friend who is not allowed to come to our school'.

"The school is completely uninterested in the fact that all Catholics are equal, one baptism for all.

"I assume it would apply the same set of rules for St Paul, who was not baptised until well after his second birthday."

St Bernadette's, one of Brighton and Hove's highest-achieving state schools, was given special praise in Ofsted's annual report to the Government in February and received an award for outstanding results in national tests.

It is thought to be the only school in the country which enforces a selection policy based on the age of pupils when they are baptised.

Headteacher Bernadette Connor declined to comment.