A scientist advising the British government on the coronavirus pandemic says it might be possible to loosen some lockdown measures by the end of May.

The U.K. has been in effective lockdown since March 23, with schools, bars, many shops and gathering places shut and people told to go out only for essentials or exercise.

Imperial College London epidemiologist Neil Ferguson, who sits on the government’s scientific advisory committee, says “we want to move to a situation where at least by the end of May that we’re able to substitute some less intensive measures, more based on technology and testing, for the complete lockdown we have now.”

He told the BBC that if the number of cases began to fall soon, then “we will be able to move to a regime which will not be normal life, let me emphasize that, but will be somewhat more relaxed in terms of social distancing and the economy, but relying more on testing.”

Authorities are imploring Britons not to flout the lockdown rules on what’s expected to be a warm, sunny weekend.