In the 2015 federal election, both of the main opposition parties (the federal Liberals and NDP) promised to implement electoral reform no later than the next scheduled election. The NDP has long supported Mixed Member Proportional, a hybrid system proposed by the Law Commission in which voters would cast two ballots (one for a riding representative and one for their preferred party, but from a regional and open list). By comparison, the Liberals led by Justin Trudeau promised to review numerous electoral reform options through an "all party parliamentary committee" and to implement the changes in time for the next election. Trudeau promised to make the 2015 election "Canada's last first-past-the-post election". There are divisions within the Liberal Party over which alternative system would be better (some prefer a proportional voting system, while others want a single member constituency preferential model); however, the promise by the Liberals, who won a majority in the House of Commons, created expectations that some sort of change will be introduced.