Transportation Minister Steven Del Duca was scrambling Tuesday to explain what happened to the plows, sanders and spreaders purchased for contractors who didn't have adequate equipment to clear Ontario highways of ice and snow.

The opposition parties say Del Duca has been boasting for months about putting over 150 new pieces of equipment on Ontario's highways since 2012, but only on Monday did his ministry clarify that the government never actually purchased any equipment.

Del Duca's staff told The Canadian Press on Monday that taxpayers didn't in fact purchase the snow-clearing equipment, leading to opposition attacks during Tuesday's question period.

"The government has done nothing but brag about buying new equipment to prop up the failed agreements," Progressive Conservative Leader Patrick Brown told the legislature. "Did the contractors give them receipts? Pictures? Has he even seen the vehicles or did the minister just hand over millions of dollars? What did you do?"

The auditor general reported in April that the government was incurring additional costs of about $15 million a year because of the purchase of the snow plows and sanders. The government says the $15 million covers the cost of additional work it requested of the contractors, such as clearing passing lanes and highway shoulders.

The New Democrats also took the Liberals to task for the confusion surrounding the matter of who paid for the new snow plows and who owns them. Like the Conservatives, the NDP said the government wasn't ensuring Ontario roads and highways are safely maintained.

"Your government awarded winter maintenance contracts to companies that didn't have the proper equipment and knowingly had the residents of Ontario drive on unsafe roads last winter," said NDP critic Wayne Gates. "Who will own the equipment that the people of Ontario spent millions of our hard-earned dollars to purchase now that these contracts have been cancelled?"

Del Duca said private companies that were given government road-maintenance contracts, even though they didn't have enough equipment to do the job, were told to buy plows and sanders and charge the government to lease them.

"We effectively pay our contractors for service," the minister told the legislature. "They are required to fulfil their equipment complement to provide that service, which means that we pay a contract price to the contractor and they, in turn, purchase or lease the equipment itself to satisfy what's required."

The Conservatives questioned Del Duca's claims.

"The government spins this by denying they bought any new equipment; but they say they gave money to these companies to buy new plows," said Brown.

Auditor general Bonnie Lysyk found that having enough equipment to clear highways of snow accounted for only 15 per cent of the criteria on which contractors were evaluated for the government contracts.

Lysyk found the government pays $1.7 million a year in additional costs for 13 pieces of snow-clearing equipment for the lowest bidder on one road contract worth $700,000, even though the second-lowest bidder had enough plows and could have done the job "at a significantly lower cost."