It returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom, elected by the first past the post system of election.
From 1950 up to (and including) 1970, it was the safest Labour seat in the United Kingdom.
The constituency was created for the 1918 general election, and abolished for the 1983 general election.
The constituency consisted of the urban districts of Abercarn, Abertillery and Nantyglo and Blaina.
The political parties had been making preparations for an election to take place and by the Autumn of 1939, the following candidates had been selected;