You could put a Wirralian and a Boltonian in the same railway compartment and swear that they came from opposite poles of the old empire.1970, The Bedside "Guardian", volume 19, page 195:
For the true Wirralian, his home is "over the water" from Liverpool and the rest of Merseyside.1981, Kenneth Burnley, Portrait of Wirral, page 13:
Wirralian
adj
Etymology From Wirral + -ian.
1
From or pertaining to the Wirral peninsula.
There is no place called Wirral: it is purely a hundred name. Undeniably the people of that part are a clique with a Wirralian outlook.1938, Edmund Vale, How to see England, page 20:
2008 June 2, Stephen Baxter, A personal reflection on a Wirralian life, Liverpool Daily Post