It was a source of considerable personal pride to the former Manchester MP Jim Callaghan, who has died aged 91, that after a lifetime spent seeking to improve health services in his constituency, his efforts were recognised, 10 years after his retirement from the House of Commons, when the local NHS centre was renamed in his honour. On visiting Callaghan House, in Cross Street, Heywood, he was also able to commend the health authority for ensuring that the disabled facilities complied with legislation he had introduced at Westminster.

He was a profoundly modest man – he used to introduce himself as “the other James Callaghan” – who had been born into the rough, tough streets of Manchester and who well understood the poverty of the urban slums in which he was raised and the acute social deprivation he later witnessed as a teacher in the city.

Eldest of five children of Norah and Jim Callaghan, he had an Irish Catholic background and a father who was at one time a lorry driver. He never disclosed details of his early education, but there was a hint of a difficult street-fighting youth. He admitted once that there was a time when he was “constantly in trouble”, that he could find his way blindfold to the local hospital and that the doctors there would greet him with: “Not you again, Callaghan!”

By his mid-20s, however, he had secured qualifications from Manchester and London universities and started teaching sport in junior schools in his home city before being appointed in 1959 as a lecturer in art at St John’s and Openshaw Technical College (now the Manchester College). He retained a love of art and sport throughout his life, but never forgot the postwar slums that politicised him. Having joined the Labour party, he was elected to Middleton council in 1971 and then pulled off the considerable feat of narrowly taking the Middleton and Prestwich parliamentary seat from the Conservatives in the “Who Governs Britain?” general election of February 1974.

“Little Jim”, as he became known at Westminster (he was considerably shorter than his famous namesake), was widely liked, as much by his fellow MPs as by his constituents. He was initially embarrassed when occasionally mistaken for James Callaghan (who became prime minister in 1976), particularly when travelling abroad and finding himself unexpectedly upgraded by foreign dignitaries. In time he grew to laugh and enjoy it.

MPs liked him because he was decent, diligent and stuck to his principles without pretension or pursuit of promotion. He was correspondingly popular in the constituency because his views were similar to many of those he represented: he was an old-style Tribune group leftwinger, opposed to Europe, nuclear weapons and power, and what he regarded as unnecessary bellicosity in the Falklands and the Gulf.

Most significant, though, was his pursuit of every government to secure better education, to improve the health service and to speak out in defence of those who had no voice of their own. He was never afraid to express controversial views and was an early advocate of a ban on public smoking. He was concerned about excessive violence being shown on television because of the possible impact on family life and repeatedly attempted to outlaw boxing as a sport because of what he described as the terrible tragedies and hazards involved.

His sincerity was evident in all his speeches and he was consequently heard with respect. Early in his parliamentary career he successfully proposed a private member’s bill, amending the law on disabled access to commercial buildings, and was subsequently promoted to become parliamentary private secretary to the chief secretary to the Treasury, Joel Barnett, giving him a toehold on the lowest rung on the ladder for political promotion.

Within three months, in early 1976, he nevertheless voted against his own Labour government – obliging the prime minister, Harold Wilson, to stage a vote of confidence – and he was predictably sacked. By an odd quirk, he later found himself in a popularity contest with Barnett, his parliamentary neighbour, for the redrawn constituency of Heywood and Middleton, which he won in 1983.

During Michael Foot’s tenure of the Labour leadership, Callaghan sat briefly on the opposition frontbench as a junior spokesman on Europe from 1982, but thereafter his career was concentrated on parliamentary work out of any sort of limelight.

He was an assiduous member of Commons’ select committees on transport, education and national heritage. He sat on the Commons’ catering committee and on the Speaker’s panel of committee chairmen. Having reached the age of 70, he stood down at the 1997 election, glad to have more time to pursue his interests in photography, art and sport, and to spend time with his wider family.

He is survived by a brother, Joe, three sisters, Norah, Pat and Maureen, and eight nephews and nieces.

• James Callaghan, politician, born 28 January 1927; died 29 March 2018