Spekesoftly.
I don't think you understand.
Absolute minima has nothing to do with Cat 1, Cat 2 etc. Absolute minima is connected to the landing runway. Each runway in the UK has an absolute minima. As controllers you should know what that minima is for your landing runway. If an aircraft passes the 1000 ft point when the RVR is below the absolute minima it is your duty to report this to the CAA.
eg. The absolute minima for 06R at MAN is 550 metres. If an aircraft passes the 1000 ft point when the RVR is 500 metres, he WILL be reported. Simple and clear. No landing clearance will be issued, only the advice mentioned above.