By SIMON CALDWELL

Last updated at 00:50 11 July 2007

Pope Benedict XVI declared yesterday that Christian denominations other than his own were not true churches and their holy orders have no value.

Protestant leaders immediately responded by saying the claims were offensive and would hurt efforts to promote ecumenism.

Roman Catholic- Anglican relations are already strained over the Church of England's plans to ordain homosexuals and women as bishops. The claims came in a document, from a Vatican watchdog which was approved by the Pope.

It said the branches of Christianity formed after the split with Rome at the Reformation could not be called churches "in the proper sense" because they broke with a succession of popes who dated back to St Peter.

As a result, it went on, Protestant churches have "no sacramental priesthood", effectively reaffirming the controversial Catholic position that Anglican holy orders are worthless.

The document claimed the Catholic church was the "one true church of Christ".

Pope Benedict's commitment to the hardline teaching comes days after he reinstated the Mass in Latin, which was sidelined in the 1960s in an attempt to modernise.

The timing of the announcement fuelled speculation that the pontiff - regarded as an arch-conservative before his election in 2005 - is finally beginning to impose his views on the Catholic Church.

The Vatican said it was restating the position set out by the then Cardinal Joseph Ratzinger in 2000 in a document called Domine Jesus because theologians continued to misunderstand it.

At that time, Anglican leaders from around the world made their anger felt by snubbing an invitation to join Pope John Paul II as he proclaimed St Thomas More the patron saint of politicians.

Bishop Wolfgang Huber, head of the Evangelical Church in Germany, said the Vatican document effectively downgraded Protestant churches and would make ecumenical relations more difficult.

He said the pronouncement repeated the "offensive statements" of the 2000 document and was a "missed opportunity" to patch up relations with Protestants.