Wiring A Winch

Hi all

I ma wiring up a 1200lb winch to the front of my defender what ampage or thickness of cable do i need from my iso switch and battery to the winch.

Cheers

James

a used 10mm squared wire to wire my 8274 and its heavy enough to run the 6 hp motor that is on it a got mine profesionaly wired and av got 2 realys and an isolator switch on the dash from the iso its only 2.5 mm cable goint to a realy that opens the second realy which is about a 120 amp with 10 mm going to the winch from the batery