Dominic Raab has not spoken to Boris Johnson since the Prime Minister was taken to hospital despite being asked to deputise for him and chairing a Cobra meeting this afternoon.
The PM is currently being treated at an intensive care unit at St Thomas' Hospital in central London where his condition is said to be 'improving'.
The pair last spoke on Saturday last week - before Mr Johnson was admitted to hospital due to persistent coronavirus symptoms.
Speaking earlier on Thursday, a Number 10 spokesperson said the PM - suffering from coronavirus - is “able to contact people if required”, but did not say how or if he is using a phone.
Mr Raab, speaking at the daily Downing Street Covid-19 briefing, said: "I think it's important particularly while he's in intensive care to let him focus on the recovery.
"We in the Government have got this covered.
"I chaired the Cobra meeting that I have just come from, we are pursuing all the different strands of our strategy to defeat the coronavirus and I'm confident we'll get there."
"He's still in intensive care but he continues to make positive steps forward and he's in good spirits."
Mr Raab, asked if he could take major decisions required in Mr Johnson's absence, replied: "I've got all the authority I need to make the relevant decisions - whether it's through chairing Cabinet updates, chairing Cobra, or indeed the morning meetings of senior ministers."
He added it was a "team effort".
Mr Raab also said it was still "too early" to lift the lockdown restrictions in place across the UK.
"It's been almost three weeks and we're starting to see the impact of the sacrifices we've all made.
"But the deaths are still rising and we haven't yet reached the peak of the virus. So it's still too early to lift the measures that we put in place.
"We must stick to the plan and we must continue to be guided by the science."
Mr Raab added: "After all the efforts everybody has made, after all the sacrifices so many people have made let's not ruin it now.
"Let's not undo the gains we've made, let's not waste the sacrifices so many people have made.
"We mustn't give the coronavirus a second chance to kill more people and to hurt our country."
Mr Johnson today spent a fourth day in hospital, where he was being treated for coronavirus.
The PM was taken into intensive care (ICU) after his symptoms persisted, and he had to be put on oxygen at St Thomas' Hospital in London.
Downing Street said he was taken into ICU as a precaution, adding that he had not required use of a ventilator.
Mr Johnson's condition was yesterday described as 'improving,' as Chancellor Rishi Sunak told the nation the PM had been able to sit up in his hospital bed.
The latest update on the leader's health comes as the UK's coronavirus death toll figures edge closer to the tragic 8,000 mark.
In England, 765 more patients have died, while in Scotland 81 have passed away and 41 have died in Wales.
Earlier today, police warned the public that those who flout coronavirus lockdown rules over the Easter weekend will face the full extent of the law.
