Boris Johnson confirmed the proposed lifting of all lockdown restrictions in England will be put back by up to four weeks.

The Prime Minister announced the setback to the final phase of his plan to end the lockdown on Monday due to concerns over the rapidly-spreading Delta variant first identified in India.

He told a Downing Street press conference that the spread of the Delta variant meant “we have obviously faced a very difficult choice”.

He said: “We can simply keep going with all of Step 4 on June 21, even though there is a real possibility that the virus will outrun the vaccines and that thousands more deaths would ensue which could otherwise have been avoided.

“Or else we can give the NHS a few more crucial weeks to get those remaining jabs into the arms of those who need them.

“And since today I cannot say that that we have met all our four tests for proceeding with Step 4 on June 21, I think it is sensible to wait just a little longer.”

Mr Johnson told a Downing Street press conference: “We will monitor the position every day and if, after two weeks, we have concluded that the risk has diminished then we reserve the possibility of proceeding to step four, and a full opening, sooner.”

The Prime Minister said he is “confident” no further delay will be necessary but was unable to rule that out, warning of the possibility that an unforeseen and “far more dangerous” variant could emerge.

He hopes deaths will be significantly reduced by July 19 because it is expected two-thirds of adults will have been offered both vaccine doses by then due to the delay being coupled with a reduction in the time between jabs for the over-40s.

For now, limits on numbers for sports events, theatres and cinemas will remain in place, nightclubs will stay shuttered and people will be asked to continue working from home where possible.

“It’s unmistakably clear the vaccines are working and the sheer scale of the vaccine roll-out has made our position incomparably better than in previous waves,” he said.

“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.”

Stourbridge News: Covid-19 vaccine doses in the UK. (PA)Covid-19 vaccine doses in the UK. (PA)

Labour accused the Government of “incompetence and indecision” and blamed the delay on border security.

Shadow health secretary Jonathan Ashworth said: “The only reason this delay is being introduced is because the Conservatives failed to secure the country’s borders and a new variant from overseas was allowed to take hold, and failed to put in measures like proper sick pay support and surge vaccinations when needed.”

The Night Time Industries Association said the delay would “drive confidence in the sector to a new low”, while pub bosses warned the delay would cost the sector £400 million.

The Prime Minister also faced a strong backlash from the public following the news stage four of the lockdown roadmap will be pushed back.

Responding to Boris Johnson’s official Twitter account, one social media user said: “Close the borders it’s not rocket science if you’d done this on the first place we wouldn’t be in this mess now.”

“The British public says no. I won’t do it anymore,“ added another.

A third said: “As long as you and all the other g7 enjoyed yourselves with no masks and no social distancing the rest of us peasants can do one.”

A fourth added: “that's all very well boris, but if you try and extend the next deadline I fear civil unrest, the country has had enough, either we unlock and live with it or we don't.”

“Bottle it,” said another.

Although some agreed with Mr Johnson’s decision.

“It is only another month, we have to be patient,I think you have done the right thing,” said one social media user.

Another added: “I agree with you Boris, might not be a popular decision but absolutely the right one.”

Ministers were expected to hold a vote over the extension in Parliament after a debate on Wednesday, with lockdown-sceptic MPs on the Tory backbenches considering a rebellion.

But the regulations will almost certainly be approved by the Commons after Mr Ashworth said the party would support extending the restrictions.