Comment by macleginn
Interestingly, the public discourse in the UK (at least what I have observed, and it was hard not to observe a lot in the last several days) does not focus much (if at all) on the insider trading angle. It's mostly that the chancellor has this important duty to first announce the new budget beofre the Parliament, and if this course of events gets distorted this is very bad for the proper procedure. Now, the sole purpose of OBR is to ensure the proper procedure, so very silly (or "damning") of them to make such a mistake.
At the same time, almost every piece of legislation in recent years has been relentlessly leaked and taken apart way before the official announcement in parliament, so this is a wee bit ridiculous.