Shop workers are being put at greater risk of violence, verbal abuse and coronavirus infection by pubs shutting at 10pm, a retail union has warned.
Usdaw said stores remaining open until later in England were likely to become “very busy” with people buying alcohol, “triggering” antisocial behaviour.
Early pub closing was brought in last week in an effort to curb increasing rates of coronavirus.
The government said it had taken “immediate action” to “save lives”.
Under the restrictions, which also apply in Scotland, pubs, bars and restaurants must shut no later than 10pm, but shops can continue selling alcohol until later.
On Monday, Greater Manchester’s Labour mayor Andy Burnham said supermarkets, convenience stores and off-licences were now “packed out to the rafters” after closing time.
Usdaw general secretary Paddy Lillis told the BBC the situation had left him “deeply concerned” for staff.
He added: “Sale of alcohol has always been a major flashpoint for violence, threats and abuse against shop workers, whether it’s age-identification or refusing a sale to someone who is already drunk, which are both legal requirements.
“Additional problems arise when licensing laws are not the same as shop opening hours or off-sales licensing hours are longer than on-sales.”
In Wales, under current rules, pubs must stop serving by 10pm and close 20 minutes after that. Shops also have to stop selling alcohol by 10pm.
Mr Lillis urged the government and councils in England to “ensure that when they bring in new rules they consider the impact on retail and the staff”.
“Stores in town and city centres are particularly at risk of becoming very busy late at night and that could make it more difficult for our members to enforce social distancing, which is essential for keeping staff and customers safe,” he said.
Restricting coronavirus transmission would “not be achieved by filling shops with late-night revellers”, Mr Lillis added.
Labour has questioned whether closing pubs earlier will help contain the spread of coronavirus.
But a government spokesperson said: “These measures strike a balance between saving lives by protecting our NHS and the most vulnerable and minimising the wider impact on the economy and schools.
“The latest data suggests a considerable rise in the infection rate from within the hospitality sector in recent weeks, so we have taken immediate action to cut the transmission rate and save lives. As with all measures, we will keep them under constant review.”
Last week, Prime Minister Boris Johnson said: “What we’ve seen from the evidence is that the spread of the disease does tend to happen later at night after more alcohol has been consumed.”
For pubs in Northern Ireland, closing time remains at 11.30pm, although First Minister Arlene Foster said last week that no decision had been reached on imposing extra restrictions.