New - Any local car parts supplier may be able to get the leaver, if its a genuine part only then you will have to go to a Toyota dealer.
Second hand - Any local car breaker or you could try something like this -
http://www.find-a-part.com there are several companies out there that are linked to many major vehicle dismantlers, you contact just them rather than ringing around. They will then forward your details to the list of breakers they have and if anyone has the part they will contact you with a price.