The UK government has delayed plans to lift the remaining COVID-19 restrictions in England.Prime Minister Boris Johnson made the announcement on Monday, citing the highly contagious Delta variant spreading rapidly throughout the country.He warned that thousands more people might die if he did nothing.It means pubs, nightclubs, restaurants and other venues won't be allowed to fully reopen for another four weeks.The final stage of lockdown had been due to end on June 21, under a plan laid out by Johnson in February.Johnson said more time was needed to fully assess the risk of reopening."We will monitor the position every day and if after 2 weeks we have concluded that the risk has diminished, then we reserve the possibility of proceeding to Step 4 and a full opening sooner. As things stand - and on the evidence that I can see right now - I am confident we will not need more than 4 weeks and we won't need to go beyond July 19th... But now is the time to ease off the accelerator because by being cautious now we have the chance - in the next four weeks - to save many thousands of lives by vaccinating millions more people."The Delta variant, first detected in India, has sparked a recent resurgence of COVID-19 cases in Britain.Health officials believe it is 60% more transmissible than the previously dominant strain, and fear it could lead to hospitals being overwhelmed again.The extra time under lockdown will also be used to speed up Britain's vaccination programme, by shortening the suggested time between doses from 12 weeks to eight.Britain currently has one of the fastest vaccine rollouts in the world.Over 41 million people have received their first dose and nearly 30 million have had both, around 57% of the adult population.