What does losing mean for Labour… and winning for Plaid?published at 02:57 BST
David Deans
BBC Wales political reporter
For Labour, tonight’s result means governing gets harder – literally by one Senedd member.
Eluned Morgan’s Welsh government now needs to find someone else to get its spending plans for the Welsh NHS, education and everything else it does. Last year it just needed the Welsh Lib Dem Jane Dodds.
Before the death of Hefin David, Labour had exactly half the seats in the Welsh Parliament and was a seat short of a majority. Now it is two seats short.
It’s also a huge psychological blow – Caerphilly having been dominated by Labour in one way or another all the way back to the 1920s.
For Plaid Cymru, this is a big deal. In a high profile by-election, the party has beaten Labour significantly.
It’s a big boost for the party months ahead of a crucial Senedd election, where its hoping it can form the next Welsh government.
