Islington Council has announced it will appeal against a judgment which decided it had bullied and discriminated against a Christian registrar. If the ruling is upheld, it would set a legal precedent binding on other employment tribunals.
Miss Lillian Ladele was threatened with the sack and intimidated at work because she asked if she could be exempt from registering homosexual civil partnerships, the tribunal ruled.
The unanimous judgment published last week also said it was discriminatory to require Miss Ladele to act against her religious beliefs.
But in an announcement this week, Islington Council said they will lodge an appeal against the decision.
In a statement the Council's said: "The decision was taken after careful consideration of the legal ruling made by the London Central Employment Tribunal."
Cllr John Gilbert said: "This isn't a decision we've taken lightly, but we believe an important question is at stake and the law must be clarified.
"Islington Council, like all councils and employers, needs to know whether we can expect employees to provide services to all sections of the community, regardless of who they are."
The council has been able to provide, in its own words, a "first class" civil partnership service to homosexual couples even though Miss Ladele has not taken part.
It is not yet known on what grounds the council will appeal.