An Air Canada affiliate plans to launch operations from Billy Bishop Toronto City Airport on May 1, posing the first competition from the controversial downtown island airfield for incumbent regional carrier Porter Airlines since it launched operations in 2006.

Air Canada said last month that a new regional affiliate–Sky Regional Airlines–would operate up to 15 daily return flights between downtown Toronto and Montreal’s Trudeau International Airport using five Bombardier Q400 turboprops leased from Air Canada subsidiary Jazz Air.

Commonly known as Toronto Island Airport, the downtown facility has stood at the center of controversy ever since City Center Aviation–a company controlled by Porter Airlines founder Robert Deluce–evicted Air Canada from the island airport in 2006. Along with Continental Airlines, Air Canada–after a series of court battles–grudgingly accepted a minority share of new slots allocated last year by the Toronto Port Authority and declared its intention to return to Toronto Island in February. However, complex leasehold negotiations with City Center Aviation forced another launch delay, until this May.