Archbishop's fears over gay marriage consequences
Proposals to legalise gay marriage cannot foresee the outcome for children or society, an archbishop has said.
The Roman Catholic Archbishop of Birmingham said the experience of growing up with a father and mother was an "invaluable lesson" in life.
The Most Reverend Bernard Longley's comments were in a letter read out in churches in the archdiocese on Sunday.
Gay rights group Outrage said bishops had chosen to portray the changes as "the end of the world as we know it".
The government plans to allow gay marriage but says it will not force religious bodies to perform services.
In the letter, the archbishop said: "Government policy cannot foresee the full consequences, for the children involved or for wider society, of being brought up by two mothers without a father's influence or by two fathers without a mother's influence."
He said society must first learn about diversity and acquire a respect for difference through the "complementarity" of parents.
The proposals have also been criticised by the leader of the Catholic church, Archbishop of Westminster Vincent Nichols.
He called the plans "a shambles" and said the government had no mandate to push them through.
David Allison, spokesman for Outrage!, said it was as if bishops of all denominations had chosen to portray the proposals "as the end of the world as we know it".
"The important thing is that it means two people who love each other are fairly recognised by the state or by the church and can live together like a conventional married couple," he said.
Peter Beck, co-ordinator of the Birmingham Green Party, said he thought Mr Longley might be following an official line.
"We do support the government proposals," he said.
"What we support is that what's important is you have two loving, caring people involved, two parents, that's the important thing."
The Archdiocese of Birmingham covers Birmingham, Coventry, Dudley, Sandwell, Solihull, Staffordshire, Stoke-on-Trent, Warwickshire, Walsall, Wolverhampton and Worcestershire.