The governing body of the Church of England, the General Synod, voted overwhelmingly to follow the lead of the police and bar ordained priests, trainees and lay staff from becoming members of racist political parties, specifically including the BNP.
It will require discplinary rules for vicars to be rewritten, and some critics claimed the move could still breach human rights and trigger employment tribunal cases because the BNP is a legal organisation.
Others warned that far-right parties could get around the rules by changing their names, or by claiming their members are merely supporters rather than official members.
However the vote was carried by 322 votes to 13, with 20 abstentions, amid claims that the BNP is trying to promote itself as a Christian group, and fears that there are “racist undertones” in the Church that leave ethnic minorities “scandalously under-represented” among clergy.
In 2004, the Synod affirmed that voting for a racist party is “incompatible with Christian discipleship” while since 2006 candidates for positions in the priesthood have been screened for racist attitudes.
However Vasantha Gnanadoss, a lay member of the Synod and a civilian employee of the Metropolitan Police, put forward a motion that the Church should follow the policy adopted by the Association of Chief Police Officers in 2004 and ban specifically its employees from joining groups that contravene race equality policies including the BNP.
It comes after a list of 12,000 names and addresses of alleged BNP members was posted on the internet, including a retired Church of England priest among five “reverends” of different denominations.
Miss Gnanadoss said: “The Church is institutionally reluctant to take any bold measures related to racism, but when it is pushed it is capable of a positive response.
“Without [this motion], the day may come when the BNP or something similar will have gained significant power in our country and the Church will stand accused of having been feeble when it could have been resolute.”
Sir Ian Blair, the former Metropolitan Police commissioner, was allowed to sit with her in the Synod chamber even though he has no official connection to the Church.
Speaking in favour of the motion during the debate, Dr Rowan Williams, the most senior cleric in the Church, said: “We have passed motions condemning racism in general in the past.
“There is a theological issue, one of whether someone who accepts their policies can conceivaby have the sensibility required of a Christian pastor who has responsibility for the whole parish.
“I think we have to name names, we have to talk about particular political organisations and not just racism in general.”
The Rev Rose Hudson-Wilkin, a vicar in east London, said the reason there are so few ethnic minority clergy is “not purely because we have nothing to say”.
She claimed: “It is because of racist undertones. They do not believe in our parishes and dioceses that ethnic minorities have nothing to contribute to the life of the Church.
“We are all nice and pally to each other but the undertone of that is racism.”
The Bishop of Blackburn, the Rt Rev Nicholas Reade, warned that the threat of the BNP would be particularly acute during the recession as the party attempts to play on Britons’ fears over jobs and public money going to immigrants.
He said: “In these difficult economic times there are always those who can be tempted to look for solutions among extreme political parties and we need to underline that the politics of hatred can never come up with a solution to our problems.”
Earlier the Archbishop of Canterbury told the Church that divisions in the Anglican Communion over women bishops and homosexuality are not completely beyond repair.
In his Presidential Address, Dr Williams said both traditionalists and liberals must accept that the other side is not going to go away, and not cling to the “fantasy” of a pure church.
He admitted that the communion between the 80 million members of the global church is “indeed a very imperfect thing”.
Last year hundreds of church leaders, mostly from Africa, boycotted a key conference in protest at the presence of liberal Americans who had consecrated a homosexual bishop, the Rt Rev Gene Robinson, while many Anglo-Catholics have threatened to leave the Church of England if women are introduced to the episcopate without provision for those who oppose the reform.
But the Archbishop insisted: “We have not yet got to the point where we can no longer recognise one another as seeking to obey the same Lord.”
He said Anglicanism had always been pragmatic and diverse, adding: “Many feel that just this is what is now threatened from both ends of our current debates, whether on sexuality or on the role of ordained women.”
Dr Williams said legislation is now being developed that could allow traditionalists to remain within the Church once women have become bishops.
“My own hope is that we may yet be able to offer the rest of the Communion some possibilities for coexistence if we could get this right.”
The bishops of the Church will now have to formulate a policy that prevents priests from being members of the BNP, and amend the Clergy Discipline Measure, which currently does not prohibit them from allegiance to any political party.