During the inter-war years, legislation moderated the circumstances in which the death sentence could be applied. The Infanticide Act of 1922 made the killing of a baby by its mother no longer a capital crime. This was extended to include one-year-old children in 1938. The minimum age for trial for murder was raised to 18 in 1933. The National Council Against the Death Penalty was founded in 1925, and abolition was considered in the abortive Criminal Justice Act of 1938.
At a time when Members of Parliament were increasingly opposed to the death penalty, the Criminal Justice Act of 1948 reopened the debate. The National Council against the Death Penalty requested a five-year suspension. The Parliamentary Penal Reform Group organised a petition against the death penalty, which was signed by 187 MPs.
The Bill that appeared before the House of Commons in 1947 contained, however, no reference to capital punishment. Opinion on abolition amongst Cabinet Ministers was divided, and the Cabinet decided on a free vote in the House of Commons on any amendment concerning the death penalty. A suspension was proposed in an amendment, and passed in the Commons with a narrow majority, but was quashed in the House of Lords. The Lords then stopped a further government amendment, proposing different degrees of murder with varying penalties.
Following these failures to reach a satisfactory conclusion, the government appointed a Royal Commission on capital punishment under Sir Ernest Gowers. The Commission deliberated between 1949 and 1953.
The Gowers Commission found that imposing definable categories of murder with associated sentences was impractical. It recommended the age limit be raised to 21 and juries empowered to decide if mitigating circumstances justified life imprisonment in place of the death penalty. The Commission recommended that the McNaghten Rules be annulled and juries left to decide on diminished responsibility on the grounds of mental health. Commission findings stated that abolition was the key issue, but the government eventually rejected the conclusions of the Commission.