Attendance at the World Petroleum Congress in Houston has been affected by concerns about the fast-spreading Omicron variant of Covid-19, though WPC organisers remain upbeat about the quality of an event that was delayed for one year to allow for an audience to be physically present.

Among those withdrawing from the event were the chief executives of BP and QatarEnergy and several energy ministers.

Standing in for BP chief excutive Bernard Looney, who opted to stay in the UK, head of BP America David Lawler told a panel on Monday morning, “Logistics and some of the things happening with Covid right now made it difficult for him to come."