As Labour Member of Parliament for the eastern Welsh valleys constituency of Pontypool (later renamed Torfaen) for almost 30 years from 1958, Leo Abse was regarded as one of the great reforming backbenchers of his age. His concerns were at the heart of the reforms that touched and revolutionised family and social life in Britain in the 1960s and 1970s: the acceptance of homosexuality, divorce and family planning, although he also interested himself in a great range of other social issues including abortion, prisons and, more recently, in vitro fertilisation.

No backbench MP could exceed his success in getting Private Member’s Bills on to the statute book. His campaign for the normalisation of homosexual acts between consenting adults was of a piece with his tenacity and eloquence. When he first introduced his Bill to end the prosecution of homosexuals in Parliament in 1961 during the Conservative Government of Harold Macmillan, it seemed an utterly hopeless cause. But his passionate commitment over the next few years paid off, and he had the satisfaction of seeing his Sexual Offences (Homosexual Reform) Bill become law under a Labour Government in 1967. He never held office, nor wished for it, though he did become the first chairman of the Select Committee on Welsh Affairs, 1979-81.

But though in the sphere of social and personal behaviour and freedoms he was a progressive, he was not in the forefront of the tide of political reform as it affected his native Wales. Welsh nationalism — certainly its vociferous Welsh-speaking wing — held no attraction for him, and he was a foe to devolution, much less independence, consistently speaking and voting against it.

Abse was opinionated and eloquent in a characteristic Welsh-Jewish manner. In his younger days he had been a great dandy given to sporting foppish waistcoats, but he was tenacious and clever. In his latter years his predisposition to Freudian analysis alarmed even his friends, and the publication of what he called “psychobiographies” of such figures as Margaret Thatcher and Tony Blair seemed to take such an approach well beyond the pale, into the realms of the far-fetched.

Times Archive, 1967: Homosexual reform Bill is passed

Mr Leo Abse said the Bill would make the country a little more civilized and bring into the community a group which had for so long been alienated

• Abse resigns from Humanists over abortion

• Mr Abse criticizes Archbishop

Related Links

• Times Archive, 1967: Homosexual reform Bill is passed

• Abse resigns from Humanists over abortion

• Mr Abse criticizes Archbishop

Leo Abse was born to a Welsh Jewish family in 1917. A younger brother was the doctor and poet Dannie Abse; his older brother was a professor of psychiatry in America. Leo Abse practised as a solicitor in Cardiff all his working life; Leo Abse and Cohen, of which he was senior partner, being the city’s largest law firm. From this work he gained his profound understanding of social injustice as well of the law’s potential for falling into hypocrisy.

He was educated at Howard Gardens High School and the London School of Economics. He joined the Labour Party at 17 in 1934 and later in the decade he clandestinely visited Spain, at a time when the Republican cause was all but lost. During the Second World War he was called up into the RAF, serving in the ranks. His service took him to the Middle East where he was placed under arrest in 1944 when he argued in Cairo in a “Forces’ Parliament” debate that the Bank of England should be nationalised.

After the war he was active in the Cardiff City Labour Party, of which he became chairman in 1951. In 1955 he stood unsuccessfully for the Conservative-dominated Cardiff North, but he was confident enough of success at a by-election at Pontypool in 1958 to advertise for a new partner in his law firm.

He swiftly made his political mark in Parliament, where he was also noted for his sartorial exuberance. In 1960 he offended some Welsh Labour members by attending his first Budget day in a grey top hat, and in 1962 he was included in the list of the world’s ten best-dressed men.

He had phenomenal success in the ballots for Private Member’s Bills, and claimed to have had more of his Bills adopted by the House than any other member in the 20th century. In 1961 he introduced a homosexual law reform Bill, which was talked out. He understood later that the Bill had been killed because the Lord Chancellor considered its subject too filthy to be discussed in Cabinet.

In 1962 he introduced his Matrimonial Causes and Reconciliation Bill, which would have allowed divorce after seven years’ separation, without either party being judged as being to blame. The Bill provoked a joint statement of protest — unprecedented on a matter of doctrine — by the Church of England, the Roman Catholic Church, the Church in Wales and the Free Church Federal Council. This unanimity provoked Abse into commenting to The Times: “It took a Jew to found the Christian Church, and it’s taking another to unite it.” Although he drastically amended the clause, by excluding people who were opposed to divorce on doctrinal or conscientious grounds, he eventually had to drop it altogether, to his great grief, in order to save the remainder of the Bill.

In 1968 he again tried to bring about divorce by consent — a move that he saw as buttressing the institution of marriage, not undermining it. The Bill was the product of months of negotiation with the Law Commissioners and a church committee presided over by Robert Mortimer, the Bishop of Exeter. The result was a compromise Bill, which allowed divorce after the irretrievable breakdown of a marriage — the situation which appertains today.

Meanwhile, in 1965 he had resumed his attack on homosexual law, this time under the Ten-Minute Rule. By this time the Government (by now a Labour one) was neutral and signified that, if sufficient support were evident, it would back a Private Member’s Bill. In July 1966 he obtained leave to introduce such a Bill, again under the ten-minute rule, by a majority of 244-100. The Home Secretary, Roy Jenkins, favoured legislation, and the Bill eventually became law as the Sexual Offences Act in 1967.