If the Mayor allowed the application it would then be referred to the Secretary of State for Communities and Local Government. Reasons for such a referral would include a Government direction that half the site is safeguarded for freight use. Since freight wharves on the Thames were safeguarded in 1997 by the then Secretary of State for the Environment, John Gummer, only one operational wharf has been lost to residential use without a full public inquiry. This was Delta/Blackwall Wharf, a major aggregates wharf redeveloped as part of the Greenwich Peninsula masterplan.