Instead of everyone - even ministers - finding out about major reforms after the arguments have been had and the brochures printed, non-kitchen cabinet members might actually get some say.
Instead of the executive imposing an idea upon the government and Parliament, it might have to make a case, think about alternative views - accept some of them even.
Illustration: John Shakespeare
Saying a policy had tested well in focus groups, or had been promised to a special interest group, or was sure to win over a particular demographic at the next election, might not pass muster as a convincing reason to implement it any more.
That's right, governing through negotiation and debate. What a concept! Smells like... democracy.