The Conservative government began hearing complaints about the Temporary Foreign Worker Program as far back as 2006, with issues ranging from concerns about not enough workers to alleged abuse of the system.

The complaints were passed along by MPs who wrote letters and emails to the ministers who have been responsible for the program since 2006.

According to an initial analysis of documents by CBC News's Power & Politics, obtained through access to information, most of the concerns came from Conservative MPs in Alberta.

On July 6, 2009, Conservative MP Rob Merrifield, wrote: "I have received quite a few complaints from Canadian workers who have been laid off during this recession, only to discover that their TFW counterparts are still employed."

On Oct. 3, 2011, Conservative MP Chris Warkentin wrote: "Alberta currently faces a shortage of workers in the service industry — particularly in the food and beverage sector. The [redacted] relies heavily on foreign workers to fill out a third of its staff."

To find out more, click the video above and watch the excerpt from Power and Politics. You can also look at the documents yourself below.