British Prime Minister Boris Johnson will detail a path out of Covid-19 lockdown on Monday to gradually reopen the battered £2.1 trillion ($2.94tn) economy, aided by one of the fastest vaccine introductions in the world. With more than 120,000 deaths, Britain has the world's fifth-highest official toll from the pandemic and suffered its biggest economic crash in more than 300 years. But a fast start to the vaccine programme and an almost two-month tough national lockdown means Mr Johnson can now set out a phased easing of the restrictions, giving priority to a return to schools and social mixing outdoors. "Our decisions will be made on the latest data at every step, and we will be cautious about this approach so that we do not undo the progress we have achieved so far," he will say, according to his office. Under pressure from politicians in his own Conservative Party to restart the economy, and from scientific advisers who fear a resurgence of the virus if he unlocks too quickly, Mr Johnson has a difficult course to chart. He has appeared much more cautious in recent months and his Health Minister, Matt Hancock, said on Sunday that any easing, such as the reopening of schools on March 8, would be followed by a couple of weeks to detect the effect on the wider population. Mr Johnson will set out four tests to be considered before each new relaxation is made, including the speed and success of the inoculation programme, the state of infection rates and the effect of any new variants of the virus. Britain moved faster than much of the West to secure vaccine supplies and has been inoculating people rapidly since December, a strategy that has driven sterling and stock markets higher on the hopes of an economic rebound. About 17.6 million people, more than a quarter of the 67 million population, have now received a first dose, behind only Israel and the UAE in vaccines per capita. The government aims to give a first dose to all adults by the end of July. Mr Hancock also said the country had recently succeeded in driving down cases of the more infectious strain first identified in South Africa. Overall daily coronavirus cases hovered about 11,000 last week, compared with a high of more than 80,000 in late December. Parliament will vote on Mr Johnson's roadmap for England after it is revealed on Monday. Leaders in Scotland, Wales and Northern Ireland will also ease restrictions in coming months.