Disclosed is a dispenser (200) attachable to the rim of a toilet bowl comprising - an upper compartment (201) for holding plurality of unit doses (202) of a hygiene composition; - a lower compartment (203) comprising inlet (204) and outlet (205) for a portion of flush water and a float member comprising a float (208) wherein said float member comprises two levers, a first lever (209) longer than a second lever (213) which are spaced apart from each other by an immovable dividing member (214) present therebetween and also extending inside said conduit (206) and wherein the movement of said levers (209, 213) is synchronous); and - a conduit (206) forming a channel between upper and lower compartments and comprising an orifice (207) for dispensing a unit dose, wherein said inlet (204) and outlet (205) is individually configured to allow water to enter faster than to exit and where said levers (209, 213) extend partly inside said conduit (206), wherein said float (208) is movable within said lower compartment (203) from a base position to a raised position and vice versa in response to quantity of water (212) in said lower compartment (203), wherein when said lower compartment is filled, said float (208) moves to said raised position thereby causing the levers (209, 213) to move further upwards inside said conduit (206) simultaneously admitting therein a unit dose (202), and when said lower compartment (203) gets substantially emptied, said float (208) moves back to said base position, thereby causing the levers (209, 213) to move downwards to align said unit dose (202) with said orifice (207).