The seat attracted five candidates in 2010, eight in 2015 (an election in which five of the deposits were refunded and three lost) and seven in 2017.

Its wards were split between Ceredigion Preseli and Mid and South Pembrokeshire.

[3] The seat was predominantly rural with both Welsh and English speaking areas.

Milford Haven has a significant port and oil industry, and tourism is also a key sector due to the Pembrokeshire Coast National Park.

Since the 2006 boundary review of Welsh parliamentary constituencies, which took effect at the 2010 general election, it consists of the Pembrokeshire County electoral divisions of: Burton; Camrose; Cilgerran; Clydau; Crymych; Dinas Cross; Fishguard North East; Fishguard North West; Goodwick; Haverfordwest Castle; Haverfordwest Garth; Haverfordwest Portfield; Haverfordwest Prendergast; Haverfordwest Priory; Johnston; Letterston; Llangwm; Llanrhian; Maenclochog; Merlin's Bridge; Milford Central; Milford East; Milford Hakin; Milford Hubberston; Milford North; Milford West; Newport; Neyland East; Neyland West; Rudbaxton; St David's; St Dogmaels; St Ishmael's; Scleddau; Solva; The Havens; and Wiston.