At the moment, the current Government guidance for both employers and employees is silent on how the CJRS interacts with annual leave / holiday pay.
However, ACAS has issued some guidance which gives examples on when it will be impractical to take holiday, among which is if the employee has “been temporarily sent home as there’s no work (“laid off” or “put on furlough”)”.
ACAS therefore seems to be suggesting here that you cannot be on furlough and holiday at the same time.
However, this does not appear to be consistent with the Scheme for the reasons below.
As such, it is strongly arguable that an employee can be on furlough and annual leave at the same time.