This issue came to the fore once more following the enactment of the European Union Act 2011, which introduced a 'referendum lock', a statutory framework requiring a national referendum to be held before further amendments can be made to the founding Treaties of the European Union. This followed on from the coalition government's pledge to obtain popular approval for any further transfer of sovereignty or powers to EU institutions. The referendum lock provision in the Act seemed to extend this pledge beyond the last Parliament by creating a manner and form requirement, which arguably binds future governments.