caron wyn jones , father of welsh first minister carwyn jones , underwent a hip operation at a private clinic in bridgend .
he paid because the welsh nhs could not perform operation soon -- and he was keen to get it done before a holiday .
ed miliband 's strategy of attacking the tories for trying to ` privatise ' the nhs backfired after the father of a senior labour politician admitted he had paid for treatment .
the disclosure came as mr miliband unveiled his general election manifesto for the nhs .