An opening blocking system for a vehicle door, wherein the system comprises: - a lever , pivotable with respect to a reinforcement element of said lever , wherein the lever comprises an actuation cam , such that an actuation on the lever causes movement of the actuation cam which in turn causes the unlocking of the door; - a blocking device , wherein the blocking device comprises fixing means for fixing to the reinforcement element , wherein the blocking device can be moved to prevent the accidental unlocking of the door; characterised in that the blocking device comprises a first section , a second section , and a break area , wherein the fixing means comprise at least one first attachment element for attaching the first section to the reinforcement element of the lever and at least one second attachment element for attaching the second section to the reinforcement element of the lever , being the at least one first attachment element arranged at the end farthest away from the first section with respect to the break area , and being the at least one second attachment element arranged at the end farthest away from the second section with respect to the break area . wherein the first section is attached to the second section through the break area , wherein the first section comprises a projection extending away from the reinforcement element , wherein the blocking device is configured such that, when the projection receives pressure, the break area breaks, releasing a movement of the first section of the blocking device to a blocking position, wherein said first section blocks the actuation path of the actuation cam . - a lever , pivotable with respect to a reinforcement element of said lever , wherein the lever comprises an actuation cam , such that an actuation on the lever causes movement of the actuation cam which in turn causes the unlocking of the door; - a blocking device , wherein the blocking device comprises fixing means for fixing to the reinforcement element , wherein the blocking device can be moved to prevent the accidental unlocking of the door; characterised in that the blocking device comprises a first section , a second section , and a break area , wherein the fixing means comprise at least one first attachment element for attaching the first section to the reinforcement element of the lever and at least one second attachment element for attaching the second section to the reinforcement element of the lever , being the at least one first attachment element arranged at the end farthest away from the first section with respect to the break area , and being the at least one second attachment element arranged at the end farthest away from the second section with respect to the break area . wherein the first section is attached to the second section through the break area , wherein the first section comprises a projection extending away from the reinforcement element , wherein the blocking device is configured such that, when the projection receives pressure, the break area breaks, releasing a movement of the first section of the blocking device to a blocking position, wherein said first section blocks the actuation path of the actuation cam . <EOS>