Professor Neil Ferguson said the B1.617.2 mutation is believed to have a “significant growth advantage” over other coronavirus variants, but this “magnitude seems to have dropped a little bit”.
Confirmed cases of this variant have soared in Bolton, Bedford, Blackburn and other communities.
Scientists warned that if it was 50 per cent more transmissable than the Kent variant it could trigger a very large third wave of infections in the UK, but if it was 20 or 30 per cent more it would be easier to contain given the high level of vaccinations.
Prof Ferguson, the Imperial College London expert whose work led to the first lockdown in March 2020, told BBC Radio 4’s Today programme: “There’s a glimmer of hope from the recent data that whilst this variant does still appear to have a significant growth advantage, the magnitude of that advantage seems to have dropped a little bit with the most recent data.
“The curves are flattening a little.
“But it will take more time for us to be definitive about that.
“It’s much easier to deal with 20 to 30 per cent than it would be 50 per cent or more.”
Prof Ferguson said the variant had been largely introduced into the UK by people arriving from India.
Scientists were now seeking to determine how quickly the variant will spread in other parts of the country.
Prof Ferguson believes it is in the balance whether the Government will proceed with the final stage of easing lockdown on June 21 given the threat from the variant.