Labour has accused George Osborne of being distracted from his day job by "personal ambitions" as he prepares to stand in for David Cameron at Prime Minister's Questions tomorrow.
Shadow chancellor Chris Leslie criticised him for opting not to respond to an opposition day debate on productivity taking place in the Commons chamber immediately after the weekly sparring session.
Mr Osborne hit back during heated exchanges in Treasury questions, telling MPs: "I never thought I'd say 'bring back Ed Balls'."
He also joked that Labour needed to work on the "productivity of its own front bench".
Mr Leslie began by asking whether the Chancellor would be leading for the Government in tomorrow's debate, to which he replied: "No I won't."
The shadow chancellor then suggested the issue was not a priority for him, adding: "I'm very surprised that you are not going to be responding on this central question.
"After all, you are going to be here acting as prime minister in PMQs tomorrow.
"If I can just bring you a little bit back to the economy and maybe rein in your own personal ambitions for a moment, I would like you to set out where productivity features in your own ambitions.
"And while we have got you today, because you are obviously not bothered about this tomorrow, can you just explain to the House, why did you fail to mention productivity at all in your March budget speech just three months ago?"
Mr Osborne replied: "I never thought I'd say 'bring back Ed Balls'.
"I think the Labour party needs to look at the productivity of its own front bench after those two dismal questions.
"I spoke in the Mansion House about the importance of raising the productivity of the UK, a challenge you know has existed for many decades.
"At the Budget, we will bring forward further proposals to tackle the productivity gap in skills, in infrastructure, in the regional imbalance of our economy.
"Maybe the Labour party could get some credible economic spokesman and they could take part in the debate."