WALKERTON, Ont. - Liberal Leader Stephane Dion took his campaign tour to the site of a deadly water contamination on Wednesday in a bid to highlight the dangers of government deregulation and cutbacks.

Dion told an audience of high school students -- the vast majority of whom won't be old enough to vote on Oct. 14 -- that a Liberal government would spend an additional $50 million to buttress Canada's food safety net.

"There is nothing more at the core of what a government should do than food safety -- to be sure the water you drink, the food you eat, is safe," Dion told the 660 assembled students of Sacred Heart High School in this southwestern Ontario community.

The Liberal pledge, he said, would add 100 additional federal food inspectors, an eight per cent increase.

While Dion linked the announcement to the listeriosis outbreak that has claimed 15 lives since tainted meat was traced to a Maple Leaf processing plant in Toronto last month, he did not say how the new federal money might have averted Walkerton's woes.

Seven people died and thousands fell ill in 2000 after the town's water supply became polluted with deadly E. coli bacteria.

A subsequent public inquiry put part of the blame on provincial cutbacks in water testing and helped lead to the defeat of the provincial Conservative government in 2003.

The federal Tories quickly pointed out Wednesday that Ontario's inquiry found that some of those provincial funding cuts had occurred under the NDP government of the early 1990s -- a government led by current Liberal star Bob Rae.

And federal New Democrats have loudly insisted that cuts to the federal food inspection regime started under the previous Chretien Liberal government during belt-tightening in the mid '90s.

Dion was joined at his school appearance by Walkerton Mayor Charlie Bagnato, who has called for a public inquiry into the listeriosis outbreak.

While the Liberal leader did not directly attribute the tainted meat to recent and unannounced changes to Canada's food safety regime by the Harper government, Bagnato has shown no such reticence.

"Governments should have learned from the mistakes that led to the tragedy in Walkerton," the mayor wrote in a blistering open letter last month.

"I am completely shocked that Mr. Harper has opted to make the same mistakes nationally that led to our disaster."

On Wednesday, Bagnato made no secret of his partisan leanings, openly promoting both Dion and the local Liberal candidate to the high school students.

It was difficult to say whether the message resonated.

At least 30 students lined up at two microphones to ask Dion questions after his address and there was enough time for about a dozen to query the Liberal leader.

Not a single question was about food safety, listeriosis or the Walkerton water woes.

The Liberal campaign flew to Saint John, N.B., on Wednesday evening, the first time the four-day-old campaign has taken to the air after busing more than 1,000 kilometres from Ottawa to Montreal, Napanee, Ont., Toronto, Walkerton and Hamilton, Ont.