I just had the same work done in the US for the same symptoms and Triumph covered it under Warranty (2006 R3 Classic - long out of factory warranty). Worth an ask if there's extended warranty coverage on that part before you pay the bill.
Norton......make **** sure that they understand that the primary TPS is located at the rear side of the throttle boddies....not the front. Them little suckers are not the same and will mess things up.