1950–1974: The burghs of Irvine, Kilwinning, Stewarton and Troon, the districts of Irvine and Kilbirnie, the electoral division of Dundonald in the district of Ayr, and the electoral division of Dunlop and Stewarton in the district of Kilmarnock.[2]
1974–1983: The burghs of Irvine, Kilwinning and Troon, the districts of Irvine and Kilbirnie and the electoral division of Dundonald in the district of Ayr.[3]
2005–present: The North Ayrshire wards of Irvine East, Irvine South, Irvine West, Kilwinning, and the South Ayrshire wards of Ayr North, Kyle, Maybole, North Carrick and Coylton, Prestwick, and Troon.
The constituency covers towns such as Irvine and parts of Kilwinning to the north, as well as the coastal resorts of Troon and Prestwick to the south. The seat also takes in a set of villages in rural South Ayrshire including the former mining communities of Annbank, Mossblown and Tarbolton alongside the villages of Loans, Dundonald and Symington.
Irvine was designated in the 1970s as a Glasgow overspill new town. In recent local council elections, the SNP have performed strongly in the town of Irvine gaining 3 Councillors to Labours 5 in Irvine and Kilwinning wards.
The coastal towns of Prestwick and Troon join the town as part of the constituency as well as outlying rural areas located south and east of Troon and Prestwick: Prestwick, Troon and their hinterlands have sustained a considerable level of support for Conservative candidates locally and as part of the Ayr constituency in the Scottish Parliament. Heathfield in Ayr North also forms part of the constituency: this area is relatively small but has been more supportive of the SNP in recent council elections.
The constituency was re-established in 2005, centred around the historic burgh of Irvine and stretching north to cover part of Kilwinning and south to cover the coastal resort towns of Prestwick, Troon and their adjacent hinterlands alongside part of Ayr. The constituency covers the 2017 electoral wards of Irvine East, Irvine South, Irvine West and a small section of Kilwinning (between the River Garnock and the B778) from the North Ayrshire Council area and Prestwick, Troon, Kyle and a small section of Ayr North (between Seaforth Road and Lochside Road in Heathfield) from the South Ayrshire Council area.[5] The remainder of the North Ayrshire Council area is represented as part of the North Ayrshire and Arran Parliamentary constituency, with the remainder of South Ayrshire being covered by the Ayr, Carrick and Cumnock Parliamentary constituency alongside parts of East Ayrshire.
The seat has mostly elected Labour Party MPs since the 1950s, with the former MP Brian Donohoe having represented the seat since its creation in 2005, and was MP for the predecessor seat of Cunninghame South since the 1992 general election. He lost his seat at the 2015 general election during an SNP landslide in Scotland, in which the SNP's Philippa Whitford was elected with a majority of 13,589 votes. At the 2017 local election the Conservatives were well ahead in Prestwick and Troon in South Ayrshire, with the SNP finishing first in Irvine in North Ayrshire. Philippa Whitford returned as the Member of Parliament for the Central Ayrshire constituency at the 2017 general election with a significantly reduced majority of 1,267 votes (2.8%) ahead of Conservative challenger Caroline Hollins-Martin.[6] At the 2019 UK election, Philippa Whitford was returned as Member of Parliament for the third time, increasing her majority to 5,304 votes (11.4%).