Challenging public policy and gagging orders

There's an interresting piece in the Guardian about the potential reluctance of charities to challenge public policy due to a fear of losing contracts with local or national governments or due to gagging clauses placed within those contracts - here:(www.guardian.co.uk/.../charities-public-policy-funding-fears)

Can the NAS confirm whether there are any gagging orders in any of its contracts with local authorities, councils, national bodies or other public institutions?