Mr Justice Horner cannot overturn the 1861 legislation, but was given the option of either “reading down” the law or granting a declaration of incompatibility.

The decision to grant a declaration of incompatibility, which means the legislation is not compatible with last month’s ruling, puts an onus on politicians in the Northern Ireland Assembly to legislate for a change.

Last month, Mr Justice Horner found that preventing access to abortion in cases of fatal foetal abnormalities (FFA) and pregnancies as a consequence of sexual crimes is unlawful.

In an “historic” ruling, the court held that article 8 of the European Convention of Human Rights is breached by the general prohibition of abortions in cases of FFA and pregnancies as a consequence of sexual crimes.

The judicial review was brought against the Department of Justice by the Northern Ireland Human Rights Commission (NIHRC).

However, the court held that failure to allow abortions in cases of serious foetal abnormality was not contrary to the European Convention. The court also held that there is neither a general right to abortion nor the protection of the right to life under the common law.

Mr Justice Horner told the High Court today: “There is near unanimity among the parties in this judicial review, and that includes the Commission, that for this court to try and read the impugned provisions in a Convention-compliant way would be a step too far.

“Having given due consideration to all submissions and the arguments raised therein, I conclude that such a view is correct.

“Accordingly, as indicated in my judgment, and for the reasons set out in that judgment and as a matter of last resort, I make a declaration of incompatibility.”

NIHRC Chief Commissioner Les Allamby, speaking after the determination, said: “We welcome the Court’s decision today to grant a declaration of incompatibility, confirming that the existing termination of pregnancy laws are contrary to human rights.

“It now falls to the Department and the Northern Ireland Executive to bring forward legislation to reflect the judgment of the Court. The Commission will await to see how the Department and the Executive will take this forward or if any appeals will be lodged.”

The Northern Ireland Executive will discuss Mr Justice Horner’s determination at a regular scheduled meeting tomorrow.