National Grid Electricity Transmission Plc is seeking an experienced and suitably qualified suppliers capable of delivering a fully integrated security solution for critical national infrastructure sites at Walham and Pentir. – Lot nr.: 1 ISS Walham, Gloucestershire National Grid Electricity Transmission Plc is seeking an experienced and suitably qualified supplier capable of delivering a fully integrated security solution for a critical national infrastructure site at Walham. Duration contract start date : 26/02/2027 12:00:00 AM Duration contract end date : 25/02/2028 11:59:59 PM – Lot nr.: 2 ISS Pentir, Gwynedd National Grid Electricity Transmission Plc is seeking an experienced and suitably qualified supplier capable of delivering a fully integrated security solution for a critical national infrastructure site at Pentir. Duration contract start date : 26/02/2027 12:00:00 AM Duration contract end date : 25/02/2028 11:59:59 PM