"the reported met. vis. at the airfield concerned shall be taken to be the flight vis" - MATS Part 11, Ch 2, para 4, VFR.
ATC decide if the zone is VFR or IFR dependent on met report. You decide if you want IFR or special VFR clearance. IFR flights have priority.
PS. Stand corrected. Precise ref: MATS Part 1, Sect 1, Ch 2, FLIGHT RULES, Para 4, Note 3.
Last edited by AC2; 2nd Jun 2004 at 15:54.