Un elfen hanfodol bwysig o’r rheoliadau, fodd bynnag, yw’r ffigur canrannol sy’n pennu’r gostyngiad i’r atebolrwydd i dalu’r dreth gyngor, at ddibenion cyfrifo faint o gymorth i’w gynnig i’r aelwydydd cymwys. Rhaid i’r ganran hon adlewyrchu’n gywir y gostyngiad yn lefel y cyllid sydd ar gael ac ni ellir pennu hynny yn derfynol hyd nes y bydd Trysorlys EM wedi cadarnhau’r swm a gaiff ei drosglwyddo. Er bod y Trysorlys wedi darparu rhai ffigurau dangosol ar gyfer Cymru ym mis Mai 2012, roedd y ffigurau hynny yn sylweddol is na’r amcangyfrifon blaenorol a ddarparwyd ganddynt. Ni chynigiwyd unrhyw eglurhad ynghylch y newid. Rydym ni o’r farn bod y ffigurau presennol yn cynrychioli bwlch ariannu o dros £20 miliwn. Byddai hwn yn fwlch rheolaidd, a chynyddol, nad oes gan Lywodraeth Cymru yr adnoddau i’w lenwi.
However, a critical component of the regulations is the percentage figure which applies a reduction to the council tax liability to be taken into account for the purposes of calculating the amount of support to be provided to eligible households. This percentage must accurately reflect the reduced level of funding available and cannot be finalised until HM Treasury has the confirmed the amount to be transferred. Whilst Treasury provided some indicative figures for Wales in May 2012, these figures were significantly lower than the previous estimates they provided. No explanation of the change was provided. Our view is that the current figures represent a funding gap of over £20 million. This would be a recurring, and growing, gap which the Welsh Government does not have the resources to cover.