Progressive Conservative Leader Tim Hudak blamed "union muscle" Friday for his party's loss of the Kitchener-Waterloo seat it held for 22 years, 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."

Horwath dismissed Hudak's comments as "sour grapes," but admitted that NDP 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 Friday.

"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."

The NDP win in Kitchener-Waterloo blocked the Liberals from getting the majority they had missed by just one seat in last October's general election.

Horwath suggested the win 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 was beaming 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.

McGuinty, who was not available to comment Friday, had engineered the Kitchener-Waterloo byelection by appointing veteran Tory Elizabeth Witmer to a $188,000-a-year post as head of the Workplace Safety and Insurance Board, convincing her to give up a seat she'd held for more than two decades.

Backed by support from teachers and public sector workers angry with the Liberals for imposing a two-year wage freeze, Fife came from behind to take the riding southwest of Toronto.

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.