It is proposed that accurate MRI staging pre-operatively will allow the correct patients to receive neo-adjuvant chemoradiotherapy (CRT), and also pre-warn the surgeons if the resection margins appear threatened so that the operation can be modified to take this into account. The primary aims of the Low Rectal Cancer Study (MERCURY II) are to assess the rate of CRM positivity rate in low rectal cancer and to assess the difference in global quality of life at two years post surgery in patients according to plane of surgery with or without sphincter preservation.