The British government will not be setting an "arbitrary target" for easing the current coronavirus lockdown, British Foreign Secretary Dominic Raab said Sunday.

Raab made the remarks amid mounting pressure from some lawmakers to scrap all restrictions by the end of April.

More than 60 Conservative Party backbenchers have reportedly backed a letter to British Prime Minister Boris Johnson, which said there will be "no justification" for restrictions to remain once all over-50s have been given a dose of vaccine.

In response, Raab told Sky News: "I don't think you can set an arbitrary target and not be evidence led, which is why the review on February 22 is so important."

Raab said he was confident the government would hit the vaccination target, but said it was too soon yet to discuss when restrictions could be lifted.

"We have made good progress ... We don't want to see that unravel because we go too far too quick," Raab told Sky news.

On Saturday, Johnson said he is "optimistic" ahead of his announcement expected on February 22 about a "road map" for easing England's lockdown.

Johnson said his plan would prioritize the reopening of schools from March 8, followed by non-essential retail and then hospitality venues.

"I'm optimistic, I won't hide it from you," he said. "I'm optimistic, but we have to be cautious."

Britain is on course to hit a target of offering a first vaccine dose against COVID-19 to its 15 million most vulnerable citizens by Monday, increasing pressure on the government to start reopening schools and loosening far-reaching lockdown measures.

Downing Street has previously confirmed that all British adults aged 50 and older are expected to be offered a first dose of the coronavirus vaccine by early May. Britain aims to offer all adults their first dose by autumn.

England is currently under the third national lockdown since the outbreak of the pandemic in the country. Similar restriction measures are also in place in Scotland, Wales and Northern Ireland.

To bring life back to normal, countries such as Britain, China, Germany, Russia and the United States have been racing against time to roll out coronavirus vaccines.

(With input from Xinhua, Reuters)