Gwendolen Morgan, of law firm Bindmans, representing Mr Miranda, said outside court that the Home Office and police had made "sweeping and vague assertions about national security".
She said Mr Miranda "does not accept the assertions they have made".
He "looks forward to the opportunity to have the Government's actions and assertions fully scrutinised" at the hearing in October, she added.
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Downpours keeping us on our toes today
The M20 in Kent has been closed in both directions after a pedestrian bridge allegedly collapsed on the motorway on Saturday.
The AA have warned of traffic jams and urged people to carry extra water in their vehicles because of the warm weather.