Yes. All unsecured amounts owed to the Canada Revenue Agency up to the date of your Proposal will be included within your Proposal.
However, you will be required to file any outstanding taxes so Canada Revenue Agency can determine the total debt owed so that they can submit a claim and vote on that amount as a creditor under the Proposal.
For any debt owed to the Canada Revenue Agency from the date of your Proposal onwards, you are responsible to pay as this is considered post-proposal debt.
If the Canada Revenue Agency has put a Writ on your home prior to filing a Proposal, this effectively makes them a secured creditor, similar to a mortgage, and this amount cannot be included in the Proposal unless they consent, or the property is surrendered.