Vince Cable has warned George Osborne against resting "on our laurels"" about Britain's economic recovery being assured.
Cable's intervention comes just two days after Osborne declared that the economy was "turning a corner" and that any questions about the coalition's strategy had been "decisively ended" by the previous two quarters of economic growth.
In a speech to business leaders at Warwick University, the business secretary warned that "a few quarters of good economic data" did not mean the economic recovery was guaranteed. The economic recovery will only be "meaningful" with strong and sustained business investment, he said.
Despite recent employment data showing part-time jobs have soared to a record high, Cable welcomed the "beginnings of a recovery story" in Britain.
"We can't rest on our laurels. The kind of growth we want won't simply emerge of its own volition. In fact, I see a number of dangers. One is letting up, just because we had a few quarters of good economic data," he said.
Although Cable warned against "letting up" in pursuing an economic recovery, the quotes trailed before his speech suggested he was going to warn ministers against "complacency".
"It isn't difficult to see evidence of confidence returning, and there are positive trends in production. Taken together with success stories like the car industry and export growth in emerging markets, we have the beginnings of a recovery story.
"Recovery will not be meaningful until we see strong and sustained business investment - and this is still 13% down on its 2008 peak and, as a share of GDP, is currently the lowest in the G7."
Cable's comments at the joint government and CBI industrial strategy conference in Warwick were seized upon by Labour's shadow business secretary Chuka Umunna, who described them as an "embarrassing slapdown" to the chancellor.
"It also reminds everyone that you can't trust a word the Lib Dems say. Vince Cable has supported the Chancellor's policies which choked off the recovery in 2010," he added.
Cable has previously clashed with Osborne, calling on the Chancellor in March to borrow more in order to revive economic growth.
Speaking on BBC Radio 4's Today Programme this morning, Cable insisted that Osborne got his tone on Monday "exactly right". Cable stressed that Britain's economy remained in a "long, dark tunnel".
"I don't want the public debate about this to become obsessive about a few weeks' data, when what really matters is the long-term change we're trying to achieve, getting Britain more outward looking, avoiding a return to the boom-bust psychology," he said.
"The point I am trying to make is that this is a long-term haul. We have got a marathon not a sprint here. It took us years of mistakes by governments to get us into this crisis, and it has taken five years to start to crawl out of it."
Cable's comments come new research by two US economists found that tax rises and spending cuts had made the economy 3% smaller.
Alan Taylor and Oscar Jorda, two independent economists, argued that over half of the economy's growth shortfall can be attributed to the coalition's cuts, when comparing the economy's shortfall in growth to forecasts by the Office for Budget Responsibility.