Born in Dublin, Simpson worked as a draper and footwear manufacturer,[1] and also became a lay preacher.
[2] Simpson joined the Northern Ireland Labour Party (NILP) and stood unsuccessfully for Stormont in Larne both in a 1945 by-election, and in the general election later that year.
[1] After his party colleague Paddy Devlin defected to the Social Democratic and Labour Party, he became the sole remaining NILP MP, and the only non-Unionist MP attending Parliament.
[3] He became regarded as the party leader; for example, the NILP's manifesto for the Belfast City Council elections of 1973 carried a foreword written by him.
[4] At the 1973 Northern Ireland Assembly election, Simpson stood in Belfast North, but fell well short of taking a seat.