OTTAWA -- Liberal leadership hopeful Marc Garneau says he's not afraid to open up constitutional negotiations in a bid to reform Canada's unelected Senate.

Garneau acknowledges there's a risk his approach could plunge the country into another sprawling round of constitutional wrangling over a host of divisive issues.

Even if the talks remained focused strictly on the Senate, he allows it could prove impossible to find provincial agreement on the kinds of reforms that should be undertaken.

Still, Garneau says political leaders shouldn't allow fear of failure to prevent them from trying to reform the Senate.

And in a jab at front-running leadership contender Justin Trudeau, he says it's better to try than to settle for the status quo.

Trudeau has said he'd focus on trying to make the existing Senate work better by appointing higher-quality senators, rather than trying to change it.