I'd argue that the reason for so many PRs is as much due to a failure to balance the budget and books. Once we can get things on an even keel, then we're in a better place in terms of planning, but ultimately the combination of insecure budgets, reduced funding, increasing operational tempo and ever changing requirements forces us to live in financial flux.
Its all well saying 'sort this at start of parliament' but look where we were 5 years ago, and look at the ops we're doing now and the kit we're using. Arguably its a totally different environment.
Current expectations are a post easter announcement,