Debates between the two party leaders have become increasingly bitter over the course of the COVID-19 outbreak. Sir Keir has accused Mr Johnson of misleading MPs at the dispatch box, while the Prime Minister has said the Labour leader is failing to "work constructively" with him in the face of the unprecedented health crisis.
The stage for today's clash has already been set, with Sir Keir Starmer attacking the Prime Minister's handling of the coronavirus crisis in a newspaper interview this morning.
Ahead of PMQs, Sir Keir told his Conservative counterpart to "get a grip" and accused him of having lost the public's trust after Mr Johnson's senior aside, Dominic Cummings, was accused of breaking lockdown to travel to Durham.
Expressing concern at the Government's response to the pandemic, he accused Mr Johnson of "winging it".
In an interview with The Guardian, he said: "I am putting the Prime Minister on notice that he has got to get a grip and restore public confidence in the Government's handling of the epidemic.
"If we see a sharp rise in the R rate, the infection rate, or a swathe of local lockdowns, responsibility for that falls squarely at the door of No 10.
"We all know the public have made huge sacrifices. This mismanagement of the last few weeks is the responsibility of the Government."
Sir Keir added: "My worry is that after a week or more of mismanagement, I'm deeply concerned the Government has made a difficult situation 10 times worse. There is a growing concern the government is now winging it.
"At precisely the time when there should have been maximum trust in the Government, confidence has collapsed."
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12.03pm update: Starmer demands answers as to who is in charge of coronavirus response
Sir Keir Starmer has demanded Mr Johnson explain who is in charge of the Government's response to coronavirus.
This morning's Daily Telegraph reported the PM was to take back "direct control" of the Government's response.
The Labour leader has said this raises questions as to who has been in charge up to now.
Responding, the Prime minister has told his counter-part to start "co-operating" with the Government to help get the UK back on its feet.
12.00pm update: And we're off!
Boris Johnson has entered the House of Commons chamber and the Speaker has called for the first question to the Prime Minister.
The latest clash between Mr Johnson and Sir Keir Starmer is underway.
11.52am update: The effect of coronavirus on the Commons atmosphere
The House of Commons has been lacking it's usual lion's den atmosphere since the coronavirus outbreak, with just 50 MPs allowed into the chamber at a time.
So far, this has appeared to play into the new Labour leader's hands - a barrister by trade, he is used to forensically articulating an argument in a court of law.
On the other hand, Boris Johnson tends to perform best in front of a crowd.
Will the Prime Minister be able to overcome the obstacles holding him back from his usual performances at the dispatch box today?
11.45am update: Starmer likely to take swipe at Cummings
With Parliament in recess last week, Mr Johnson and Sir Keir have not met at the dispatch box since the row over Dominic Cummings' trip to Durham broke out.
While the news broke nearly two weeks ago now, it is likely the Labour leader will use today as the chance to attack the Prime Minister for standing by his top aide during the scandal.