General national rules on both public and private funding of political parties and election campaigns must also be applicable to referendum campaigns, including the rules on transparency and limitation of spending and individual donations (point II.4.4. a). In the event of a failure to abide by the statutory requirements, for instance if the cap on spending is exceeded by a significant margin, the vote may be annulled. It should be pointed out that the principle of equality of opportunity applies to public funding, and that equality should be ensured between a proposal’s supporters and opponents (point I.2.2.d).