Valérie Plante captured the imagination of Montrealers with an ambitious election platform that included more affordable housing, improved mobility and even the possibility of a new Metro line.

All that could be done, she promised, without raising taxes beyond the rate of inflation.

With her first budget, reality set in.

The average tax increase for homeowners is 3.3 per cent. The rate of inflation is projected at 2.1 per cent, according to the Conference Board of Canada.

It's hard to see how this doesn't qualify as a promise broken.

Plante maintained during Wednesday's news conference — and again on Daybreak Thursday morning — that her commitment was about the property tax rate, not the overall tax bill. But that is semantics.

While homeowners will see their property tax rate increase by an average of 1.9 per cent — which is below the rate of inflation — an average borough service tax of 0.3 per cent and a 1.1 per cent spike in the water tax pushes the overall bill far beyond inflation.

"During the campaign, what I was putting emphasis on was the property tax. I'm not trying to find excuses, but this is reality," she said on Daybreak, trying to defend the increase.

"Once we took office and opened the books, and we realized what had been addressed by previous administrations and what wasn't, water infrastructure is something that was not addressed."

The additional tax revenue will go toward upgrading the Montreal's deteriorating water pipes, sewer lines and treatment plants, which had a maintenance deficit of $3.5 billion in 2017.

Constraints of governing

Water infrastructure isn't the sexiest investment, but it's necessary nonetheless. Her administration is trying to catch up after "decades of under-investment," Plante said.

"I'm counting on Montrealers to understand why we wanted to move forward with the water tax," she said, arguing the putting more money in now would prevent costly emergency repairs to the city's water mains in the years ahead.

There were other budgetary constraints that made it difficult for Plante to put more money into the priorities that got her elected.

The city will devote more than $1 billion to public security for the first time, following pricey new collective agreements with police and firefighters.

Another large chunk of the pie will go to servicing the debt.

There was no money, however, allotted to study her proposed Pink line.

Nor are there any specifics about compensation for merchants hurt by construction, or details about her pledge to eliminate the welcome tax for families buying their first home.

Those details are forthcoming, she said on Daybreak, stressing again why the city's water infrastructure needed repairs.

Credibility tested

But the opposition at city hall — and even influential members of the business community — are already calling into question her credibility.

The Chamber of Commerce of Metropolitan Montreal said in a statement the tax increase "goes against the promise made by the mayor during the campaign, which sends a disturbing signal."

Opposition leader Lionel Perez and finance critic Alan DeSousa reacted to Plante's budget Wednesday afternoon. (Radio-Canada)

Alan DeSousa, the opposition finance critic, said Plante should come clean and admit she couldn't keep her promise.

"I think it's reasonable to say look, 'we made a mistake, we shouldn't have promised that we have kept it to inflation,'" he said.

"But to try to weasel out of it, I don't think it's right."