The PM also didn't know how much a pack of Pampers nappies costs at Boots.
BP and Shell are expected to unveil bumper payouts for shareholders this week.
A leaked document reportedly shows the Treasury rejected the suggestion.
The business secretary said the plan was "more of a medium term answer" to the cost of living crisis.
Business Secretary Kwasi Kwarteng has ordered a new report into the controversial drilling process.
Shadow business secretary Jonathan Reynolds's suggestion was immediately dismissed by cabinet minister Grant Shapps.
Check your gas and electricity use before energy prices increase this Friday.
Rishi Sunak has been accused of refusing to sign off on the extra cash needed for new projects.
The US and other countries will increase exports of liquified natural gas to Europe, but the continent can't quit its reliance on Russian supplies overnight.
OVO Energy admitted its tips — which included doing housework and jumping jacks — were "embarrassingly unhelpful and poorly judged".