From the House of Commons website has the following definition of the Official Opposition...
The role of the Official Opposition is to challenge government policies, hold the government accountable for its actions and give voters an alternative in the next election. Generally, the Leader of the Opposition is the leader of the party with the second largest membership in the Commons. This person leads opposition debates and suggests changes to government legislation or alternative proposals. Each opposition party in the Commons has its own leader and appoints critics from among its members. Each critic handles a certain subject, such as health or defence. They present their party’s policies on the subject and comment on government policies.The NDP said in the last election they wanted to make Parliament work. They stated during the campaign they would not only oppose the government and hold them to account, they would also make alternative proposals to the government ie make Parliament work.
What makes The NDP different is that most opposition over the last 30 plus years have simply offered opposition and little in alternative solutions. This has cemented in many people's minds that to be effective as the Official Opposition, one must vehemently oppose and the more excited you are to oppose the better.
The NDP have been focusing attention on the fact that little gets done, largely because the opposition and government just butt heads. The NDP have decided to focus on getting things done, ie working with government to propose alternatives and or improvements to legislation and budgets rather than simply oppose.
Of course the NDP are not simply going to let the Government use its majority without making their objections known. They will in fact be very diligent in this aspect of their role. The ending of the postal lockout was an example of the NDP doing what it could to oppose the Government's agenda.
This fall will be the big test as will the budget debate in the spring. We will have to wait and see how it all plays out, whether the NDP's approach to opposition is more effective than that of the Liberals and or the Conservatives over the last 30 plus years.