The comments came as Mr Gove gave evidence to the Commons Public Administration and Constitutional Affairs Committee this afternoon. Tory MPs have been voicing deep disquiet about the civil liberties implications of a certification scheme, stressing that if cases are low it should not be necessary. But Mr Gove said there were 'frictional costs' involved with certification as testing would have to be continued for those who had not been vaccinated. Gove said there was not an 'ironclad' link between the June 21 date earmarked for the next stage of the road map out of lockdown and the possible introduction of Covid status certification. 'People have quite rightly linked Covid status certification to stage four.