Canada is taking its lumber fight against the United States to one of the most contentious elements of NAFTA – Chapter 19, which sets up trade panels to settle disputes. Ottawa filed its request on Tuesday for a binational panel under the North American free-trade agreement to strike down the United States’s punitive tariffs on Canadian softwood. The move comes as Canada takes an increasingly hardball approach to NAFTA renegotiations and just one day before talks resume in Mexico City. Chapter 19 is one of the key sticking points in NAFTA talks: The Trump administration wants to abolish the panels while Canada has vowed never to give them up. Ottawa is keen to keep Chapter 19 – and invoke the panel in the current softwood dispute – because Canada has previously emerged victorious when appealing its case through NAFTA in the long-running lumber battle.