The following persons shall be exempt from section 5(1) of the Immigration Act 1988—
(a) any person who would have been last given leave to enter the United Kingdom seven years or more before the date of the decision to make a deportation order against him but for his having obtained a subsequent leave after any absence from the United Kingdom within the period limited for the duration of the earlier leave;
(b) any person whose limited leave to enter or remain in the United Kingdom has been curtailed by the Secretary of State under section 7(1) of the Asylum and Immigration Appeals Act 1993 .