Multiple Labour sources have indicated that Corbyn is determined only to trigger the move if there is a realistic prospect of winning rebel Tory votes needed to trigger a general election.
As the official opposition, only Labour can formally table a confidence vote and usual convention is that it is granted parliamentary time as quickly as possible.
But Corbyn and his allies fear that unleashing the move this week would result in a victory for Johnson that would offer him a political boost as he heads into the summer recess.
When Labour last tried the tactic in January, Theresa May won the vote by 325 votes to 306, allowing her a temporary reprieve to try once more to get her Brexit deal through the Commons.
Although there are believed to be enough Tory MPs ready to take the ‘nuclear option’ of siding with Corbyn in a confidence vote, they will only do so if it looks like the only alternative to a no-deal Brexit.
With Johnson set to take the UK out of the EU on October 31, several MPs believe that it will be in September or October before there is a realistic chance of getting the majority needed.
In a bid to keep the new administration guessing, Corbyn will not reveal his hand before Thursday, one source said.
The Tory civil war needs to ‘fester’ longer before the move could be considered, another suggested.
Just hours before Johnson was set to be confirmed as the new Tory leader and next PM, senior cabinet minister David Gauke was the latest to say he was reluctant to vote against him in a confidence vote.
He and several other Tories believe that they have to first try to exhaust other moves to legally block a no-deal Brexit before taking the ‘last resort’ of a confidence vote in their own government – a move that would guarantee they would cease to be Conservative MPs.
Several Labour MPs had been keen to trigger a confidence vote either on Wednesday or Thursday this week, at least to put down a marker. But they have been persuaded that a delay is the smarter approach.
One Tory MP who counts himself as a member of the so-called Gaukeward squad told HuffPost UK: “We have all advised the Labour Party not to think of a no confidence vote this week.
“I would be the first one in the lobby to support Boris Johnson on a no confidence motion this week. We will all get behind an elected leader. People like me want him to succeed and want him to have a chance.”
Some in Johnson’s team were hoping for a swift confidence vote to assert his claims of party unity but will now have to navigate a difficult period when MPs return after their summer break.