"Of course the numbers of cases are relatively low at the moment - all waves start with low numbers of cases that grumble in the background and then become explosive, so the key here is that what we are seeing here is the signs of an early wave."
He added that the third wave would probably take longer to become apparent though due to the amount of people that have been vaccinated.
"There may be a false sense of security for some time, and that's our concern," he said.
Prof Gupta is a member of the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), and said that the planned ending of restrictions in June should be delayed "by a few weeks whilst we gather more intelligence."
"If you look at the costs and benefits of getting it wrong, I think it is heavily in favour of delay, so I think that's the key thing," he added.
The Environment Secretary has
told the BBC that the government would be taking things "one step at a time."
He told the broadcaster: "We can't rule anything out. We know this has been a difficult pandemic, a dynamic situation. We have to make that judgment a couple of weeks before.
"It will only be by then that we will see the impact of the latest easement we made on 17 May."
The government will make a final decision on 14 June as to whether restrictions can be lifted on the 21st.
