The PQ was elected last September on a platform that included a call for resource revenues to more than double, with a new royalty formula that would bring provincial coffers another $388 million per year.
Its election messaging promised big changes and had accused the previous Liberal government of selling out Quebec's resources.
But with only a minority government, and in the face of concerns from the business community, the PQ has toned down its previously stated aspirations on this file as it has on several others.
That recurring theme has also been seen on the language front, where the PQ has put forward a bill that is only a fraction as severe as what it promised before the election.
The new mining plan, announced Monday, would increase royalties by 15 per cent — to a total of $370 million.
Mining companies would be required to pay a minimum annual tax, based on extraction amounts, and a royalty on profits ranging between 16 and 23 per cent.
The plan also calls for more transparency and will make public the annual sums raised from each individual company.
"It's not like we left hundreds of millions of dollars sitting on the sidewalk — that's not true," said Finance Minister Nicolas Marceau.
"If it had been possible to go get more, we would have gone to get more."
He said he was pleased that all mining companies would wind up paying some royalties — compared with last year when only half of them paid some.
The new rates would have to be approved by the legislature.
Opposition parties slammed the plan, accusing the PQ of having fostered unnecessary investor uncertainty in order to score political points last fall.
One party critic actually brought a toy truck to a news conference; that was to mock a dramatic PQ election ad in which a mining truck had left behind nothing but a few meager pebbles for Quebecers.
"This truck is now a symbol of the hypocrisy of the Parti Quebecois," said Coalition member Francois Bonnardel, holding up the toy.
Industry groups also accused the government of harming Quebec's competitiveness with the changes, just three years after the Liberal government had already increased rates. The Charest Liberals raised rates to 16 per cent, from 12 per cent, in 2010.
But Quebec solidaire, the legislature's smaller left-leaning party, accused the government of having backed down in the face of the mining lobby.
The government said it had to move cautiously, given the recent drop in metals prices. Marceau said it would have been "irresponsible" to stick to the original target.