A drive assembly for initiating medicament delivery by means of a medicament delivery device (1; 1'), the drive assembly comprising: a driver (21; 21') configured to be rotationally driven, an actuator sleeve (15; 15'), a delivery member cover (7; 7') configured to be moved linearly relative to the driver (21; 21'), between a first delivery member cover position and a second delivery member position, wherein the delivery member cover (7; 7') is configured to cause the actuator sleeve (15; 15') to move from a first position to a second position, and a resilient blocking member (17; 17') configured to surround the driver (21; 21'), and configured to be arranged radially inside of the actuator sleeve (15; 15'), wherein the blocking member (17; 17') is configured to engage with the driver (21; 21') to prevent rotation of the driver (21; 21') relative to the blocking member (17; 17'), the actuator sleeve (15; 15') being configured to move from the first position relative to the blocking member (17; 17'), in which the drive assembly is in an initial state and in which the actuator sleeve (15; 15') is configured to prevent the blocking member (17; 17') from moving radially outwards, causing the blocking member (17; 17') to engage with the driver (21; 21') and thereby prevent the driver (21; 21') from rotation, to the second position in which the drive assembly is in an activation state, wherein when the actuator sleeve (15; 15') is moved from the first position towards the second position the actuator sleeve (15; 15') is configured to set the blocking member (17; 17') free to disengage from the driver (21; 21'), enabling the driver (21; 21') to rotate, and wherein the blocking member (17; 17') has arms (17b; 17b') extending radially inwards and the driver (21; 21') has radially outwards extending protrusions (21c; 21c'), wherein the arms (17b; 17b') are configured to engage with the protrusions (21c; 21c') when the actuator sleeve (15; 15') is in the first position,. a driver (21; 21') configured to be rotationally driven, an actuator sleeve (15; 15'), a delivery member cover (7; 7') configured to be moved linearly relative to the driver (21; 21'), between a first delivery member cover position and a second delivery member position, wherein the delivery member cover (7; 7') is configured to cause the actuator sleeve (15; 15') to move from a first position to a second position, and a resilient blocking member (17; 17') configured to surround the driver (21; 21'), and configured to be arranged radially inside of the actuator sleeve (15; 15'), wherein the blocking member (17; 17') is configured to engage with the driver (21; 21') to prevent rotation of the driver (21; 21') relative to the blocking member (17; 17'), the actuator sleeve (15; 15') being configured to move from the first position relative to the blocking member (17; 17'), in which the drive assembly is in an initial state and in which the actuator sleeve (15; 15') is configured to prevent the blocking member (17; 17') from moving radially outwards, causing the blocking member (17; 17') to engage with the driver (21; 21') and thereby prevent the driver (21; 21') from rotation, to the second position in which the drive assembly is in an activation state, wherein when the actuator sleeve (15; 15') is moved from the first position towards the second position the actuator sleeve (15; 15') is configured to set the blocking member (17; 17') free to disengage from the driver (21; 21'), enabling the driver (21; 21') to rotate, and wherein the blocking member (17; 17') has arms (17b; 17b') extending radially inwards and the driver (21; 21') has radially outwards extending protrusions (21c; 21c'), wherein the arms (17b; 17b') are configured to engage with the protrusions (21c; 21c') when the actuator sleeve (15; 15') is in the first position,.