The charity, Catholic Caring Services, was also told that it should remove the word 'Catholic' from its title.

Bishop of Lancaster Patrick O'Donoghue has told the Ashton-based charity it will no longer have the support of the Church if it disobeys its teachings.

Changes in equality laws mean that from January next year it will be illegal to discriminate against gay couples who wish to adopt.

But the charity said it will continue to respond to the plight of the neediest of children who require adoptive homes.

Bishop Patrick has also told the charity if it goes ahead and complies with the anti-discrimination law, thus going against the Church's stance on homosexuality, it will no longer be working on behalf of the Diocese of Lancaster.

He said: "I find it unthinkable, indeed heartbreaking, that Catholic Caring Services, so linked to the Catholic Church since its inception, would abandon its position and capitulate to recent same-sex adoption legislation.

"On grounds of conscience, formed by faith, we believe that same-sex partnerships do not provide the essential characteristics necessary for the wellbeing and development of the child."

He also warned that the charity could not call itself Catholic and go against the teachings of the church "unless you have fully exhausted all possible legal alternatives".

And the future of its three buildings in Preston – in Wellington Road, Tulketh Road and Beech Grove – could be under threat as a review of their leases is carried out.

The charity will also be disqualified from any financial contributions from the Lancaster Diocese.

As well as offering adoption services for children, Catholic Caring Services also works with deaf people and people with learning difficulties.

It also has offices in Maryport, Barrow and Carlisle in Cumbria.

>> Bishop blasts colleagues on gay adoptions

>> Vote in our latest web poll