An identification tag applicator comprising: a body having a pair of applicator jaws (18,20) attached thereto, wherein one of the jaws is pivotable relative to the body; a manually-operated actuator pivotably attached to the body and adapted to move the pivotable applicator jaw between open and closed positions; wherein the actuator comprises: a lever having a first lever end pivotably attached to the body, and a second lever end; a lever biasing member which biases the lever towards a first position in which the pivotable jaw is in the open position; a first link member having a first link end pivotably attached to the pivotable applicator jaw, and a second link end having a first locking surface; characterized in that a second link member has a third link end which is pivotably attached to the second lever end, and a fourth link end which has a second locking surface and which is pivotably attached to the second link end; wherein when the lever is in the first position the first and second link members lie in the same plane and the first and second locking surfaces (40,42) abut one another to hold the link members in the same plane as the lever is moved from the first position, and the second and fourth link ends are connected by a link pin which is offset from the plane of the link members (32,34); and wherein the pivotable applicator jaw includes a projecting member adapted to force the link members (32,34) to pivot relative to one another about the link pin so that link members move out of the plane when the applicator jaws (18,20) reach a closed position. a body having a pair of applicator jaws (18,20) attached thereto, wherein one of the jaws is pivotable relative to the body; a manually-operated actuator pivotably attached to the body and adapted to move the pivotable applicator jaw between open and closed positions; wherein the actuator comprises: a lever having a first lever end pivotably attached to the body, and a second lever end; a lever biasing member which biases the lever towards a first position in which the pivotable jaw is in the open position; a first link member having a first link end pivotably attached to the pivotable applicator jaw, and a second link end having a first locking surface; characterized in that a second link member has a third link end which is pivotably attached to the second lever end, and a fourth link end which has a second locking surface and which is pivotably attached to the second link end; wherein when the lever is in the first position the first and second link members lie in the same plane and the first and second locking surfaces (40,42) abut one another to hold the link members in the same plane as the lever is moved from the first position, and the second and fourth link ends are connected by a link pin which is offset from the plane of the link members (32,34); and wherein the pivotable applicator jaw includes a projecting member adapted to force the link members (32,34) to pivot relative to one another about the link pin so that link members move out of the plane when the applicator jaws (18,20) reach a closed position. a lever having a first lever end pivotably attached to the body, and a second lever end; a lever biasing member which biases the lever towards a first position in which the pivotable jaw is in the open position; a first link member having a first link end pivotably attached to the pivotable applicator jaw, and a second link end having a first locking surface; characterized in that a second link member has a third link end which is pivotably attached to the second lever end, and a fourth link end which has a second locking surface and which is pivotably attached to the second link end; wherein when the lever is in the first position the first and second link members lie in the same plane and the first and second locking surfaces (40,42) abut one another to hold the link members in the same plane as the lever is moved from the first position, and the second and fourth link ends are connected by a link pin which is offset from the plane of the link members (32,34); and wherein the pivotable applicator jaw includes a projecting member adapted to force the link members (32,34) to pivot relative to one another about the link pin so that link members move out of the plane when the applicator jaws (18,20) reach a closed position.