The Archbishop of Westminster said today he was "disappointed" with Government plans to legalise same-sex marriages.
The Most Reverend Vincent Nichols, who is president of the Catholic Bishops' Conference of England and Wales, said: "Equality and commitment are both very important and we fully support them.
"But equality and commitment do not amount to marriage."
He said: "To respect a life-long partnership is one thing and to call it a marriage, if you like to annexe the territory of marriage, is something quite different."
The coalition Government announced in September that it will legislate for same-sex marriages before the next general election.
A public consultation on how to make civil marriage available to same-sex couples is to be launched in March of next year.
The archbishop said: "I am very disappointed that the Government seems to be choosing this direction.
"I respect the Prime Minister's insistence and emphasis on the importance of equality in relationships and the vital importance of commitment.
"Those are things that we recognise as very important for the health of society.
"But commitment plus equality does not equal marriage.
"The distinctive nature of marriage is something that is very important to the wellbeing of society because it is the foundation of family life as we know it and as it is experienced by the vast majority of people."
The archbishop also spoke about the "inadequate" response towards victims of abuse within the Catholic church.
The issue has come into sharp focus in recent weeks following Lord Carlile of Berriew's decision to strip monks of control at a west London school beset by sex abuse.
The peer said he hoped his decision to take powers away from Ealing Abbey would "set a template" for other schools.
The Most Reverend Vincent Nichols said: "The personal commitment of bishops attending to, understanding and responding to victims of abuse is there to be seen.
"What we have not achieved and what we recognise as inadequate is the extent of that response, its consistency and the way in which it is sustained over longer periods."
He said the National Catholic Safeguarding Commission (NCSC) had been asked to renew its efforts to develop a "care pathway" for victims to help the church respond "appropriately and sensitively to their needs at every stage".
During the plenary meeting this week, the bishops also discussed how to improve their support of other vulnerable groups, such as victims of trafficking, as well as Christian groups in Palestine, the archbishop said.
Father Marcus Stock, general secretary of the Catholic Trust for England and Wales, outlined their desire to ask the Secretary of State for assurance that voluntary aided schools will not be disadvantaged in a period of Government cuts.
He also spoke of plans to improve the performance of some Catholic schools to ensure "that the Catholic sector has schools which offer a high standard of Catholic education to our pupils".
The archbishop also read out a newly approved Prayer for the Queen, to be read in every parish to commemorate the Queen's Diamond Jubilee next June.