The popular retail complex Gunwharf Quays has been evacuated with an order for all premises to be cleared by 23:00 to allow Royal Navy Bomb Disposal experts to start moving the 500kg bomb, which was discovered during dredging works.
According to the Royal Navy, at midnight tonight bomb disposal experts will tow the device into open waters 1.5 miles east of the Isle of Wight to dispose of the device in a controlled explosion.
The controlled explosion is likely to be carried out in daylight hours early tomorrow morning (Friday).
Wightlink ferries in and out of Portsmouth will be affected by the operation. According to the ferry operator, customers travelling on the 23:59 Portsmouth to Fishbourne sailing must check in at least 30 minutes prior to departure. Vehicles or foot passengers arriving after this time may have to travel on the next sailing which departs at 03:00.
This latest incident comes just weeks after a torpedo was also brought up during dredging works.
UPDATE FRIDAY – It is understood the bomb was successfully destroyed at around 07:00 this morning.