There is provided a carton comprising a side wall (4) comprising a first panel (6) connected to a second panel (8), a first lower flap (16) hingedly connected to the first panel, the first and second panels having free ends, a second lower flap (18) hingedly connected to the second panel, a hinged locking base panel (30) hingedly connected to the first lower panel and an inner base panel (36) hingedly connected to the second lower panel, a plurality of strengthening tabs (54,56,58,60) attached to the hinged base locking panel or the inner base panel, the first lower flap being folded over and affixed to the first panel, the second lower flap being folded over and affixed to the second panel, the hinged base locking panel being folded along a hinge line (34) thereof and affixed to the inner base panel, in which substantially diagonal weakening lines (80,82,84,86) are positioned on the lower flaps.