By Maura Forrest The federal government wants construction on a planned high-speed rail line between Toronto and Quebec City to begin within four years. On Thursday, Canada-U.S. Trade Minister Dominic LeBlanc said the government’s new major projects office will work to speed up engineering and regulatory work on the Alto high-speed rail line. “This is a very exciting project in a very densely populated area,” he told reporters at a press conference in Montreal. LeBlanc made the comments at the Port of Montreal, where a planned expansion is among the first five projects under consideration for fast-track approval through the federal government’s major projects office. Alto was not among the five projects unveiled Thursday, but the government has listed it with others identified for future development. Former prime minister Justin…