British Prime Minister Boris Johnson on Monday warned of a "rough winter" ahead even though things may be "looking good" for July 19 to be the so-called "terminus point" marking an end to all lockdown restrictions in the country.

His warning came as the UK registered a further 9,284 daily COVID-19 infections on Sunday, a day before the government had planned to ease all lockdown measures until the Delta variant forced a month-long delay into July.

"You can never exclude that there will be some new disease, some new horror that we simply haven't budgeted for or accounted for," said Johnson, when asked about further lockdowns in future.

"But looking at where we are, at the efficacy of the vaccines against all variants that we can currently see, I think it's looking good for 19 July to be that terminus point," he told reporters.

He indicated that the cases of the Delta variant of COVID-19, first identified in India, are rising at a rate of about 30 per cent a week, with hospitalisations and intensive care admissions "roughly the same".

"I think what the scientists are saying is that things like flu will come back this winter, we may have a rough winter for all sorts of reasons, and obviously there are big pressures on the NHS. All the more reason to reduce the number of Covid cases now, give the NHS the breathing space it needs to get on with dealing with all those other pressures, and we are certainly going to be putting in the investment to make sure that they can, he added.

Johnson was addressing reporters during a visit to the National Institute for Biological Standards and Control, part of the Medicines and Healthcare Products Regulatory Agency, to announce his aim to increase research spending from nearly 15 billion pounds a year to 22 billion pounds by 2025 as part of plans unveiled earlier by Downing Street to build the UK into a global science superpower.

"We want to use the public investment to trigger the waves of private investment that we need," he said.

Meanwhile, latest National Health Service (NHS) figures revealed that more than 1 million COVID-19 vaccines were booked in two days following the invitation on Friday for all adults in England to come forward for vaccination.

People rushed to book 1,008,472 appointments in just two days an average of more than 21,000 every hour, or six every second on Friday and Saturday, the NHS said.

"The NHS Covid vaccination programme is gathering momentum the finishing line comes into sight, said Sir Simon Stevens, NHS chief executive.

"It is fantastic to see so many young people coming forward to do their bit in the battle against the virus, protecting themselves, their friends and their family over 3.5 million people under the age of 30 have already had a first dose, he said.