Johnson has stood by Cummings, who is accused of breaking the UK's lockdown restrictions by driving 260 miles across England in March to stay with his parents while his wife was sick with Covid-19 symptoms.
Professor Stephen Reicher, a member of the UK Scientific Pandemic Influenza Group on Behaviours (SPI-B), responded on Twitter to Johnson’s defense of Cummings.
“Boris Johnson has trashed all the advice we have given on how to build trust and secure adherence to the measures necessary to control COVID-19,” he tweeted.
“Be open and honest, we said. Trashed. Respect the public, we said. Trashed. Ensure equity, so everyone is treated the same, we said. Trashed. Be consistent we said. Trashed. Make clear 'we are all in it together'. Trashed."
“It is very hard to provide scientific advice to a government which doesn't want to listen to science. I hope, however, that the public will read our papers ... and continue to make up for this bad government with their own good sense.”
In an interview with BBC on Sunday, Reicher added: "I'm not particularly concerned what happens to Dominic Cummings -- it's what happens to the rest of us."
"If we undermine the unity between the population and the government, if people lose trust and lose adherence, if they stop complying with the measures which have contained the infection, then all of us will lose out because the infection will spike again and many more people will die."
Reicher's comments have been echoed by his SPI-B colleagues.
"People have to feel that everyone's doing the same thing and pulling their weight in the same way. And once you start to see that crumble, that's a problem," said University College London health psychology professor Robert West, another government adviser.
"But even more problematic, I think, unfortunately, in relation to the prime minister's statement on it, is that in interpreting the rules he seemed to be blurring the boundaries," West said.
"And another very important principle with this kind of behavior change is that the rules have to have very clear boundaries."
"As soon as they start to get leaky, then people start to say, 'Okay I'm sure I must be in this exceptional case.'"