It's a well recognised fact that Japanese knotweed is one of the most pernicious plants ever to be introduced to the British isles. I understand that local councillors have a duty to control knotweed infestations. As these infestations can blight private houses, it is essential that these controls are in place, and yet even a cursory observation of mostly urban areas show that control measures seem not to be being applied. Would the First Minister consider reissuing guidance, and perhaps a reminder to local councils, of their duty in this regard?