It was one of the most consistently safe seats for Labour; since the end of the Second World War, the Labour candidate had always won Aberavon with a majority at least 33%, and with the exception of 2015, the Labour candidate has also always won an overall majority of the vote in the seat. In 2015, Kinnock only won 48.9% of the vote in Aberavon, against a surge in the vote for the UKIP candidate; however, in 2017, Kinnock's vote share rose by 19.2 percentage points, the biggest increase in the Labour vote in the seat's history, and his majority increased to 50.4%, the highest for an Aberavon MP since 2001. The 2017 result also made Aberavon the safest Labour seat in Wales, however the seat saw a significant swing against Labour in 2019.
Boundaries
Map of boundaries 2010–2024
1918–1950: The Borough of Aberavon, the Urban Districts of Briton Ferry, Glencorwg, Margam, and Porthcawl and part of the Rural Districts of Neath and Penybont.
1950–1983: The Borough of Port Talbot, the Urban Districts of Glyncorrwg and Porthcawl, and part of the Rural District of Penybont.
1983–1997: The Borough of Afan, and the Borough of Neath wards nos. 3 and 6.
1997–2010: The Borough of Port Talbot; and the Borough of Neath wards of Briton Ferry East, Briton Ferry West, Coedffranc Central, Coedffranc North, and Coedffranc West.
2010–2024: The Neath Port Talbot County Borough electoral divisions of Aberavon, Baglan, Briton Ferry East, Briton Ferry West, Bryn and Cwmavon, Coedffranc Central, Coedffranc North, Coedffranc West, Cymmer, Glyncorrwg, Gwynfi, Margam, Port Talbot, Sandfields East, Sandfields West, and Tai-bach.
Commenting on the 1983 boundary changes to the constituency when moving the 2000 Loyal Address of the Blair Government in Parliament, the seat's then-MP Sir John Morris, who would retire at the 2001 general election, said:
"It is a happy tradition on this occasion to refer to one's constituency and to the people who sent one here....Whatever may occur in future, I would deplore the loss of the Member-constituency link. When, after 23 years, I lost part of my constituency, I missed the friendship of two generations. My constituents and I had grown up and grown older together."
^ abcdefghCraig, F. W. S. (1969). British parliamentary election results 1918-1949 (1 ed.). Glasgow: Political Reference Publications. ISBN0-900178-019. Page 556
^ abcdefgCraig, F. W. S. (1971). British parliamentary election results 1950-1970 (1 ed.). Chichester: Political Reference Publications. ISBN9780900178023. Page 576
^"Politics Resources". Election February 1974. Politics Resources. 28 February 1974. Archived from the original on 11 August 2011. Retrieved 2 February 2021.
^"Politics Resources". Election October 1974. Politics Resources. 10 October 1974. Archived from the original on 11 August 2011. Retrieved 2 February 2021.
^"Politics Resources". Election 1979. Politics Resources. 3 May 1979. Archived from the original on 11 August 2011. Retrieved 2 February 2021.
^"Aberavon and Neath Results"(PDF). UK Parliamentary Elections May 2015 results. Neath Port Talbot County Borough Council. Archived from the original(PDF) on 5 October 2015. Retrieved 16 September 2015.