The government has published amended legislation which comes into force on the 18th March 2016 to make Enhanced DBS checks mandatory for governors in maintained schools. This is retrospective, so governors without DBS certificates appointed prior to 1st April 2016 must obtain one by 1st September 2016. Those appointed after April 1st 2016, must apply for one within 21 days. This now means that all governors, in whatever kind of school, maintained, independent, academy or free school, must have an Enhanced DBS certificate.
You can find the legislation here:
The School Governance (Constitution and Federations) (England) (Amendment) Regulations 2016