That is absolutely reprehensible. This is precisely why blackouts are such a bad idea. It turns out they are extraordinarily easy to game.
If you have no economic policy announced the Saturday before the election then you're going in to the election with NO policy and you're not allowed to talk about what you'll be doing in regard to the economy in that last week.
It is crazy to give the public the costings of your promises 48 hours before the election. The average person isn't never going to have or want to take the time in that period to really look into what is released and the liberal party know that.
What if an event happens 6 days before the election and politicians are asked to comment on it?