The funding, which will be split between 117 trusts, comes alongside attempts to reassure members of the public that it is safe to visit A&E departments during the Covid-19 pandemic.
“Thanks to the hard work and tireless efforts of NHS staff throughout the pandemic, our A&Es have remained open for the public,” the prime minister said in a statement.
“It is vital that those who need emergency treatment this winter access it, and for those who remain concerned about visiting hospitals, let me assure you that the NHS has measures in place to keep people safe.”
Hospitals will be able to use the funding to expand waiting areas and increase the number of treatment cubicles to boost A&E capacity, while social distancing rules and hygiene measures are in place to protect patients from Covid-19.
It is hoped that the projects will be completed by the start of next year so hospitals can handle a potential spike in cases during the peak of winter.
“Our NHS did an amazing job to ensure emergency care continued to be available for everyone who needed it during the peak of this pandemic,” health minister Edward Argar said.
“Today, we are announcing the details of the Trusts across the country who will receive a share of £300m to upgrade their A&Es and support emergency care to help them to continue to deliver safe and accessible services throughout the normally busy winter period.”
The government added that the funding will allow the NHS to continue to maintain the Nightingale hospitals in England until the end of March and expand its flu vaccination programme.
The Nightingale hospitals, which were built during the first wave of the pandemic but barely used, have already cost an estimated £220m, according to government figures.
It follows a stark report commissioned by Sir Patrick Vallance, the government’s chief scientific adviser, which warned that the combination of a resurgence of coronavirus and a deadly flu outbreak could cripple NHS services and lead to thousands of deaths.
The report, published last month, said the NHS would be unable to respond to a surge in cases like it did earlier this year due to added pressure from winter flu, a backlog of delayed urgent operations and increases in staff sickness.
In a “reasonable worst case scenario”, the report found this could lead to up to 120,000 extra hospital deaths if no steps are taken to control the virus.
It recommended ministers and health chiefs plan for the winter with a major expansion of the Test-and-Trace system, the roll-out of a major flu vaccination scheme and a nationwide disease surveillance system.