In October 1965 the Llyn Celyn reservoir opened, and there was a sizeable Plaid Cymru-organised demonstration. A year later, Gwynfor Evans won Plaid Cymru's first Parliamentary seat in Carmarthen. But according to some commentators, Capel Celyn did not play a major part in Gwynfor Evans's victory: in addition to Carmarthen's long distance from Tryweryn, they claim that Plaid Cymru's victory owed as much to an anti-Labour backlash in the constituency's mining communities as it did to Plaid's successful depiction of Labour's policies as a threat to the viability of small Welsh communities.