Yep 1261, and being the good little trainnie that I am
Mats prt 1, section 2, chapter1, 16.2.5
A landing aircraft, which is considered by a controller to be dangerously positioned on final approach, shall be instructed to carry out a missed approach. An aircraft can be considered as 'dangerously positioned' when it is poorly placed either laterally or vertically for the landing runway.