It is possible and within the rules, but the grand Coalition will be severely punished by the Canadian voter next election.
You, as a Liberal, should be very wary of this. This will forever change the nature of politics in Canada, effectively regulating the Liberals to a rump of a coalition.
English Canadians will not take kindly to the BQ running the country. Also, the BDers will not take kindly to being in bed with the Ad-Scam people.
I can't figure out why Harper and Co. are backing down on this.
A couple of months on the bench will do more for the CPC than 4 years in power ever could.