How to find Cardinal’s letter to the Cabinet?

Does anybody know whether there’s a public archive which might have a copy of Cardinal Cormac Murphy-O’Connor’s letter to the Cabinet? It apparently says:

We believe it would be unreasonable, unnecessary and unjust discrimination against Catholics for the Government to insist that if they wish to continue to work with local authorities, Catholic adoption agencies must act against the teaching of the Church and their own consciences by being obliged in law to provide such a service

but I’d be interested to see the whole thing…