Stephen Reicher, professor of psychology at the University of St Andrews, said blaming the public undermines trust and threatens compliance with coronavirus restrictions.
He instead recommended a focus on positive messaging, praising the “remarkable and enduring resilience of the great majority of the population”.
The expert, a member of the government’s Sage scientific advisory group, warned that tougher enforcement would ruin any chance of a partnership between the public and government, which “only the virus will benefit from”.
Speaking at a press conference on Tuesday, Patel said a minority of people are “putting the health of the nation at risk by not following the rules” and supported a tougher police approach to lockdown rules.
Watch: Priti Patel’s message to rule-breakers
“If you do not play your part, our selfless police officers... will enforce the regulations and I will back them to do so,” she said.
Patel said officers are aiming to issue fines quicker where people are clearly breaching regulations and that almost 45,000 fixed-penalty notices have been given out since March.
However, Prof Reicher said a more positive message would be more effective at discouraging rule-breaking.
“Patel is disastrously wrong in nearly every way: Lack of public compliance is NOT the problem: by and large people ARE complying and the areas where they are not are more due to practical barriers than lack of motivation,” he wrote on Twitter.
In a comment piece last week for the BMJ medical journal, Prof Reicher and John Drury from the University of Sussex said the way people’s adherence to coronavirus restrictions has been portrayed is “spectacularly wrong”, focusing on pandemic fatigue, “Covidiots” and house parties.
They said headlines should “highlight the remarkable and enduring resilience of the great majority of the population – including those who have been most subject to blame such as students and young people in general – even in the absence of adequate support and guidance from government”.
Prof Reicher’s latest comments follow reports that ministers are considering toughening up lockdown rules.
Writing on Twitter, Prof Reicher said the rules “are too flexible” and that “harsh enforcement... is ineffective, undermining consent and further alienating the public”.
“All in all, if you wanted to design the worst possible approach, destroy the possibility of a partnership between public and government in fighting the pandemic, this would be it,” he warned.
“It is the perfect anti-policy and only the virus will benefit from it.”
Patel insisted the rules are clear.
She said on Tuesday that “we all have to exercise our judgment and be very conscientious as to how we act”, adding: “We are in a pandemic.
“The British public are absolutely sensible, they are conscientious, they understand the stay-at-home message.”
Watch: England’s lockdown rules