By Catherine Morrison The NDP promised Sunday to protect tenants through a program of national rent control, while the Conservatives focused their campaign trail message on addictions treatment. NDP Leader Jagmeet Singh said in Halifax in the morning that his party would tie federal housing funding for provinces and municipalities to tenant protection policies like rent control. The NDP says housing and rent prices in Canada have doubled since 2015 and the average asking rent hit $2,109 per month in January. The party says it also wants to ban fixed-term leases, “renovictions” and other practices it says are aimed at pushing people out of their homes and driving up rents. The NDP says it would also prohibit the use of artificial intelligence to co-ordinate rent increases. Conservative Leader Pierre Poilievre,…