Except as provided by the following provisions of this section, the validity of a decision of the Secretary of State on—
shall not be questioned in any legal proceedings whatsoever.
If, in the case of any such appeal or reference, the appropriate agency or the other party desires to question the validity of the decision of the Secretary of State on the grounds—
the appropriate agency or, as the case may be, the other party may, at any time within the period of six weeks beginning with the date on which the decision is made, make an application to the High Court under this section.
On any application under this section, the High Court may by interim order suspend the operation of the decision to which the application relates until the final determination of the proceedings.
If the High Court is satisfied, on an application under this section—
the High Court may quash the decision.
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In this section—
"decision" includes a direction; and
"other party" —