The seat fell vacant after the incumbent MP, Huw Irranca-Davies of the Labour Party, chose to resign following his selection to contest the coterminous Ogmore constituency in the Welsh Assembly election.[2][3] On 23 March 2016, Irranca-Davies was appointed Crown Steward and Bailiff of the Manor of Northstead the process by which resignations from the House of Commons are permitted.[4] Irranca-Davies had been the MP for the seat since a previous by-election in 2002. Irranca-Davies had originally announced that he would seek Labour's nomination for the Welsh Assembly's Ogmore in October 2015, stating that if he was selected he would resign his Westminster seat.[5] Irranca-Davies successfully contested his Assembly election. Irranca-Davies was not obliged to resign upon his nomination, though following the Wales Act 2014, which came into effect during the 2016 Assembly election, he would have had to resign his Westminster seat following his Assembly victory. Given that in both the Assembly and Westminster Ogmore was considered a safe seat for Labour his early resignation allowed the by-election to be held on the same day rather than forcing voters to go to the polls again a few weeks later.
Candidates
Bridgend County Borough Council published the statement of persons nominated on 8 April 2016. This showed that five candidates that contested the election.[6]
Abi Thomas stood for Plaid Cymru. The Liberal Democrats selected Janet Ellard, a former teacher and now volunteer manager for a youth homeless charity.[9]
The incumbent party (Labour) selected Chris Elmore as their candidate; Elmore prevailed in the election, winning the seat.[10]