Caerphilly County Borough Council’s Labour group has held both seats in a two recent by-elections.
Arianna Passmore, a 27-year-old music teacher, won Risca East ahead of Plaid Cymru candidate Matthew Farrell with 400 votes out of 679.
The by-election was triggered by Cllr Passmore’s mother Rhianon vacating the seat following her election as Islwyn AM earlier this year.
Cllr Passmore said: “We did a lot of door knocking and issues that came up, such as social housing, is what I’ll be working on. The result was down to the hard work of everyone in my campaign.”
In Gilfach, where former council leader Harry Andrews stood down due to ill-health, Bargoed town councillor Lindsey Harding received 254 of 489 votes to win.
Cllr Harding said: “I spent a lot of time speaking to people, and fly-tipping is a growing concern to look at.
“It was a tough campaign. Plaid Cymru had a lot of people canvassing and commiserations to their candidate Ken Houston.”
Despite coming second in both wards, Plaid Cymru group leader Colin Mann said he was encouraged by the results with the share of the party’s vote in Gilfach increasing to 35%.
Both elections were held on Thursday, October 6. In Risca East, the turnout was just 14.5% while in Gilfach it was 22.8%.
Labour’s council leader Keith Reynolds said he was disappointed at the low turnouts but was delighted that both seats had been retained.
Voters across Caerphilly County Borough will be going to the polls in May next year to decide which party gains overall control of the local authority.