Type 2 Diabetes and Haemochromatosis

Having been recently diagnosed with both conditions it seems logical to me that weekly venesections are likely to effect the accuracy of HBA1c test results given that the test measures blood glucose level average over the last 3 months or so.

My question therefore is, is this in fact the case? and if so is there any compelling evidence in the form of research or otherwise that I can present to my GP to convince him to prescribe an NHS accurate blood glucose monitor?