TORONTO -- Progressive Conservative Leader Tim Hudak blamed "union muscle" Friday for his party's loss of the Kitchener-Waterloo seat it held for more than two decades, and predicted Premier Dalton McGuinty would quickly try to "kiss and make up" with Ontario's public sector labour leaders.

The Tories lost both byelections Thursday as the Liberals held Vaughan and the New Democrats made a historic breakthrough in Kitchener-Waterloo, winning the riding for the first time ever.

The NDP bused in public sector union "troops" from across the province to help them take the riding from the Conservatives, said Hudak, who had to back down from a claim that union volunteers had been brought in from outside Ontario as well.

"We were up against a tsunami of public sector union bosses, their troops," he said.

"The (NDP) won the seat, they got a new member, but this is dangerous for our province and it's an ominous development if the Liberals move back into bed with the public sector union bosses."

Hudak didn't mention that private sector unions campaigned for the Conservatives in the Vaughan byelection, where the Tories came second, and said the public sector union bosses would now have more power in the legislature to fight against a wage freeze and cuts to government spending needed to eliminate a $15-billion deficit.

"I hope I'm wrong, but I am worried that you're going to see an arms race between the NDP and the Liberals to see who can get closest to public sector union power," he said.

"There is a lot of strength in public service unions -- we've got to take this seriously and I think it's dangerous and ominous for the province to see that power on display."

NDP Leader Andrea Horwath dismissed Hudak's comments as "sour grapes," but admitted the party's candidate, Catherine Fife, got the "Cadillac of campaigns" with the party pulling in all its resources to get her elected, including 700 volunteers.

"I would say that our campaign had no more or no fewer resources than anybody else, but ultimately, you can't put a volunteer into a ballot box," Horwath said.

"It takes a message and a vision and a candidate to actually move the people, and I think we had the right mix of all of those things in Kitchener-Waterloo."

Hudak blaming the unions for the loss is "bilge" -- the kind of political jabber that goes on when politicians have to manufacture some kind of excuse, said Barry Kay, a professor at Waterloo's Wilfrid Laurier University.

"The Conservatives went into this election with every opportunity, they really had better organization on the ground because of the Witmer years," he said, referring to veteran Tory Elizabeth Witmer, who held the riding for 22 years.

There were lots of New Democrats that came in from out of the riding to get Fife elected, but that's not the only explanation for her win, he said. Fife was well-known in the community and was more smooth and experienced than her main competitors.

"But should this be seen as a knock on Hudak? Of course it should," Kay said. But he'll probably stick around for the next election.

It was also a knock on McGuinty, who engineered the Kitchener-Waterloo byelection by appointing Witmer to a plum post as head of the Workplace Safety and Insurance Board.

"He wanted to make an issue of the majority government, and the people pretty clearly said no to that," Kay said. "They don't think the government is competent enough to have a majority."

The Liberals ended up in third place, dropping to 24 per cent of the popular vote from 36 per cent in the general election last October.

But the Liberals preferred to focus on Hudak's misfortunes rather than how their push for a majority backfired on them.

"I understand he's depressed today. I mean, it was very obvious that he was down in that press conference," said Economic Development Minister Brad Duguid.

"But vilifying the unions and blaming them for the loss of a riding the Tories have held for 22 years -- I think that borders on irresponsibility. We don't take that approach."

The government is in "very tough discussions" with teachers and doctors right now, but they have a "ton of respect" for what they do and will keep working with them to eliminate a $15-billion deficit, he said.

"We're a governing party. Byelections are tough," Duguid added. "It's not a bad record for byelections for a governing party, so we're very pleased by the results last night."

The Liberals held on to Vaughan, the riding just north of Toronto vacated by former finance minister Greg Sorbara, with Steven Del Duca taking 51 per cent of the popular vote to easily defeat Progressive Conservative Tony Genco. The NDP was a distant third.

Horwath suggested her party's win in Kitchener-Waterloo hasn't emboldened her to try and topple the minority Liberals, who'll need the help of one of the other parties to pass legislation, especially next spring's budget. But she was beaming Friday as she spoke about the NDP's future prospects.

"Across this province, in regions where it's never happened before, people see New Democrats as the best option for change, and in my books, that's pretty darn exciting," she said.