Ms Ladele claimed Islington Council had discriminated against her
The Supreme Court has ruled against a Christian registrar who was disciplined by Islington Council for refusing to conduct same-sex civil partnerships.
Lillian Ladele claimed she had been discriminated against for refusing to go against her religious conscience.
In 2008 an appeal tribunal overturned a previous decision by an employment tribunal that the north London council had discriminated against her.
The Supreme Court has now refused her permission to challenge that ruling.
Miss Ladele said she might take the case to the European Court of Human Rights.
She added that she was "disappointed" by the Supreme Court's decision to reject her appeal application.
Miss Ladele, who became a registrar in 2002, refused to conduct civil partnership ceremonies "as a matter of religious conscience".
During an employment tribunal hearing in July 2008 she claimed she was harassed and discriminated against by Islington Council.
The hearing found she had faced discrimination, but that decision was overturned on appeal in the December of the same year.
The December ruling was upheld by the Court of Appeal in 2009, prompting her to challenge the ruling in the Supreme Court.
In a statement, Miss Ladele said: "I am naturally disappointed by the Supreme Court's rejection of my application for appeal.
"In my case, one set of rights was trampled by another set of rights.
"That cannot be right in a free and democratic society."
Mike Judge, from the Christian Institute, which backed her case, said: "Christians are being pushed to the sidelines of public life.
"Our nation's highest court has effectively told them their concerns are not of general public importance."
Terry Sanderson, president of the National Secular Society, said: "Had Ms Ladele's case succeeded it would have completely undermined the equal treatment under the law for gay people and unlocked the floodgates to many other damaging challenges to the equality legislation."