My hon. Friend Marsha De Cordova and I have asked numerous written questions about the shocking 461% increase in the number of personal independence payment claims disallowed for the non-return of the AR1 review form between 2017 and 2021. The Minister, sadly, has no idea why the increase has happened, or by extension whether vulnerable people are being left struggling to manage, as the Department does not collect information on the reasons for the non-return of the AR1 form. So I ask the Minister again today: when will he take action to investigate this issue?