What did the great coalition propose in order to put an end to political instability?

The Great Coalition was a grand coalition of political parties that brought the two Canadas together (Canada East and Canada West) in 1864.[1] The previous collapse after only three months of a coalition government formed by George-Étienne Cartier and Conservative John A. Macdonald and liberal George Brown, (the sixth government in six years) had demonstrated that continued governance of Canada East and Canada West under the 1840 Act of Union had become untenable.[