London, England - The main barrier to dialogue between Christians and Muslims is the failure of some countries in the Islamic world to respect freedom of worship, the country's leading Roman Catholic said on Tuesday.
When Christians are persecuted in those countries, Muslims in Britain have a duty to speak up in their defence, said Cardinal Cormac Murphy-O'Connor, leader of the Catholic Church in England and Wales.
"Dialogue will be impossible as long as minds are closed, as long as adherents of either faith believe that we have nothing to learn from the other," the cardinal said in a speech to the Oxford Centre for Islamic Studies.
"The main obstacle to that dialogue is the failure, in a number of Muslim countries, to uphold the principle of religious freedom."
Tensions between Britain's Muslim and non-Muslim populations were exacerbated by last year's July 7 bombings in London, which killed 52 people and were carried out by four British Islamist extremists.
Christians and non-believers alike urged Britain's 2.7 million Muslims to condemn the bombings, and the vast majority did. Some Christians have also urged Muslims to be more vocal in their condemnation of abuses in Islamic countries abroad.
"Where Christians are being denied their rights, or are subject to sharia law, that is not a matter on which Muslims in Britain should remain silent," said Murphy-O'Connor, who speaks for around 4 million Catholics in Britain.
He said there were "rising tensions" in the British Muslim community "which are spilling out on the edges of that community in an adherence to fundamentalist or nostalgic doctrines which approve violence".
The cardinal drew a parallel between the experience of Muslims in Britain now -- many of whom complain of Islamophobia -- and that of Catholics in Britain in the 1970s, when sectarian violence in Northern Ireland was at its height.
"There is much in our Catholic experience -- when being Catholic and Irish in the 1970s was to be equated in the minds of some with terrorism -- that must surely lead us to sympathise," he said.