Jarrow MP Kate Osborne took on the PM over rail strikes and a wave of anger among workers at the cost-of-living crisis.
She said: "Tens of thousands of people were marching through London last weekend protesting against this out-of-touch Government.
"Rail workers are on strike, Royal Mail workers, NHS workers, teachers and even barristers are on the verge of taking industrial actions. All workers are struggling to cope with the worst cost-of-living crisis in history.
"Ministers are planning to boost city bosses pay whilst demanding wage restraint for everyone else.
"So can the Prime Minister tell me, when is he going to stop meaningless soundbites and instead start supporting working people across our country?"
Mr Johnson said: "If she wants to support the working people of this country, can I suggest she gets off the picket line... and has a word with her leader, and supports the travelling public of this country who want to see a reduction in their costs of transport, which this Government is delivering."
In a post on Twitter after the session, Ms Osborne responded: “Boris Johnson had no answer to my Q instead attacking me for standing up for workers.
"Tories are on side of bankers not people who are suffering.”
The session also saw Mr Johnson has been accused of “blaming everyone else” for problems facing the country, amid claims he has “rolled over” on bankers’ bonuses.
Labour leader Sir Keir Starmer told the Prime Minister the country is “screaming” for him to “get on with your job” and resolve the industrial dispute hitting train services.
He added Mr Johnson is more focused on increasing bankers’ pay rather than “those who are running the country”, as he contrasted Government calls for wage restraint against reports the Government wants to reduce controls on City bosses’ pay.
But Mr Johnson claimed Labour would take the UK “back to the 1970s” and said Sir Keir does not have the “gumption to speak out against the rail strikes”.
Ahead of key by-elections in Wakefield and Tiverton and Honiton, Sir Keir opened Prime Minister’s Questions by paying tribute to the candidates.
In reference to Conservative Nadeem Ahmed, Sir Keir said: “In particular, the plucky Conservative candidate for Wakefield, he is standing even though his own colleagues think he is so useless they held a vote of no confidence in him.”
As Tory MPs looked on puzzled, Sir Keir added: “Does the Prime Minister hold any personal interest in seeing if the public will vote for a Tory that even his own side don’t think is up to it?”
Mr Johnson replied: “I have absolutely no doubt that the people of this country and the people of Wakefield, and the people of Tiverton and Honiton, would much rather vote for a solid Conservative Government than for a Labour Party, their enablers and acolytes in the Liberal Democrats, the karma chameleons of British politics.”
Sir Keir said Mr Johnson and Transport Secretary Grant Shapps “haven’t attended a single meeting, held a conversation or lifted a finger to stop” the rail strikes.
He added: “But I did note that on Monday they did find time to go to a lavish ball where the Prime Minister sold a meeting with himself for £120,000… If there’s money coming his way, he’s there.
“So rather than blame everyone else, why doesn’t he do his job, get round the table and get the trains running?”
Mr Johnson said the Government is doing “everything we can” to prevent the strikes, before adding: “We know why he won’t condemn the strikes, we know why even now he hasn’t got the gumption to call out his MPs for going out to support the pickets.”