TORONTO -- Ontario's finance minister was hard-pressed Monday to explain why he continued to declare publicly that the government would meet an election pledge to cut auto insurance rates despite being aware that keeping the promise would be challenging.

The Liberal government failed to cut auto insurance rates by 15 per cent by its self-imposed deadline of August 2015 -- a promise that was part of a deal to get NDP support for the 2013 budget when they were still a minority government.

Premier Kathleen Wynne said last week that her government "always knew it was a stretch goal."

The opposition parties said this was news to them, as the government consistently held out the promise as an achievable one.

When asked about Wynne's "stretch goal" comments Monday before a cabinet meeting, Finance Minister Charles Sousa noted that the 2014 election delayed the passage of legislation the government said would reduce rates for drivers.

"The moment we came into an election, the moment the delays were occurring, we knew that we were going to have challenges," he said Monday.

But when the government introduced the legislation aimed at tackling insurance fraud and inflated towing costs in July 2014, following the election that gave the Liberals a majority, Sousa insisted the 15-per-cent goal could be met by the following August.

In October of 2014 Sousa again said the target could be met.

When the legislation passed the next month, Sousa still spoke of the August 2015 goal and did not suggest it couldn't be met.

The second-quarter rates for 2015 were posted in July and had only declined on average by 6.46 per cent since August 2013. Sousa said the plan to tackle auto insurance fraud and reduce costs was working, but the government wanted to "go even further."

"Our reforms have sent rates lower on average over the last two years and there's more to do to reduce rates by 15 per cent on average," Sousa said, with no mention of it being a "stretch goal."

On Monday he called it "an ongoing issue."

"It's not at any one point or one date that matters to me, it's just the ongoing ability for us to reduce the cost of claims to further reduce our insurance premiums," Sousa said.

NDP critic Jagmeet Singh said the election only delayed the business of the legislature by little more than a month.

"That doesn't explain the 2 1/2 years," Singh said.

"If something is a priority the government can do it. They haven't made reducing premiums a priority."