The court decided the refusal to give her the cash amounted to sex discrimination on the part of the UK Government.

The woman, known as MB, was refused the female state pension after she chose not to annul her marriage.

MB said she preferred to stay married to her wife “in the sight of God.”

In a potentially landmark ruling the court decided that a person who has changed gender does not have to annul the marriage they entered into before that change, to receive a pension.

Under the 2004 Gender Recognition Act, trans people gained the right to formally change their gender by obtaining a legally-recognised "gender recognition certificate".

But such a document could not be issued to a married person who did not have their union annulled on the basis of their gender change.

MB was born a male in 1948 and married a woman in 1974.

MB began to live as a woman in 1991 and underwent sex reassignment surgery in 1995.

MB reached the age of 60 in 2008 and at that time applied for a retirement pension from the state.

That application was rejected on the grounds that, in the absence of a full gender recognition certificate, she could not be treated as a woman for the purposes of determining her statutory pensionable age.

MB challenged that decision before the UK courts.

She claimed that the provision stating that she must not be married constituted discrimination prohibited by EU law.

The UK Supreme Court asked the ECJ whether such a situation is compatible with the directive.

The ECJ ruling stated: “Persons who have lived for a significant period as persons of a gender other than their birth gender and who have undergone a gender reassignment operation must be considered to have changed gender.”