The interview came after Mr Johnson announced only “essential” businesses should remain open as the UK goes into lockdown for three weeks.
The government will then review the situation to decide whether to relieve or intensify the stringent measures.
All retail outlets must remain in lockdown with the exception of supermarkets and pharmacies. Petrol stations, bicycle shops, home and hardware shops, laundrettes and dry cleaners, bicycle shops, garages, car rentals, pet shops, corner shops, newsagents, post offices, and banks are also allowed to remain open.
Good Morning Britain airs weekdays on ITV at 6am.