OTTAWA—Parliament’s budget watchdog is predicting another multibillion-dollar increase in the cost of a new fleet of warships for the Royal Canadian Navy, pegging the price for what was already the largest military procurement in Canada’s history at more than $77 billion. Parliamentary budget officer Yves Giroux’s latest estimate is $17 billion more than the government’s stated price for the 15 warships, which are to be built in Halifax over the next two decades and form the navy’s backbone for most of the century. Giroux’s estimate is in a highly anticipated report released Wednesday that is likely to set the stage for some tough discussions—and heavy industry lobbying—on whether Canada should push ahead on the project or change tack. To that end, the budget officer’s report includes a number of potential scenarios designed to provide a clearer picture of what options are available to the government should it decide to go …