Health Secretary Matt Hancock says the Government has formally asked for Pfizer's Covid-19 vaccine to be assessed by regulators - and roll-out could start next month.
Mr Hancock told a Downing Street press conference the company had already begun submitting data to the MHRA and would submit its full data in the coming days.
He said the speed of the roll-out of a vaccine would depend on the speed it could be manufactured at the Pfizer factory.
He said: "What I can say about timing is that if - and it still is an if - the regulator approves a vaccine, we will be ready to start the vaccination next month with the bulk of the roll out in the new year.
"We're heading in the right direction but there is still a long way to go.
"Coronavirus remains a grave danger right now."
“This is another important step forward in tackling this pandemic,” he added.
"If a vaccine is approved it will of course be available across the UK from our NHS, free at the point of delivery according to need, not ability to pay."
Vaccinations centres are being set up across the country, hospitals will have hubs to vaccinate staff and GPs are creating community teams
Earlier, Mr Hancock called the vaccine roll-out programme “one of the biggest civilian projects in history” and confirmed volunteers were currently being trained.
He told BBC Radio 4’s Today programme: “There is training under way now.
“We’ve changed the law to change the number of clinically qualified people who can vaccinate because this is going to be one of the biggest civilian projects in history.
“It will be led by the NHS, who have of course the annual experience of a mass vaccination programme in flu, and it will involve GPs, it will involve the broader NHS as well, and hospitals.
He said the “deep freezers” were already “stabilising over the last few weeks” in order to be ready for the Pfizer vaccine, which needs to be stored at -70C, and confirmed the NHS would have “access to any resources of the state they might need” to assist with the mass administering of vaccines.
