A closure for a container comprises a circular closure plate (2, 4), integral with the outer edge of which is a depending skirt (8), integrally connected to the lower end of which by means of a resilient annular integral hinge (10) is an annular flange (12), which extends generally upwardly and inwardly. The closure also includes a cutter assembly which includes a cutting blade (38) and is mounted to rotate about the center of the closure plate (2, 4). The integral hinge (10) has a hole formed in it through which the cutting blade (38) extends. Rotation of the cutter assembly about the center of the closure plate thus results in cutting of the integral hinge (10) and thus in release of the closure plate (2, 4) and the depending skirt (8) from the annular flange (12).