Wikipedia's article of the day on its main page today is a reference ot the House of Lords decision in Pepper v Hart. The case established the ability of English courts to use legislative history in interpreting unclear provisions of legislation. The full article goes into some detail about why the history had not been available before (parliamentary privilege under the 1689 Bill of Rights – the courts must not criticize Parliament) and why it might be a bad idea now (it would be too much work for lawyers giving advice or drafting to have to wade through Hansard all the time).
There is a paragraph on the Canadian experience – is it accurate? Of course our courts do 'criticize' Parliament in holding legislation ultra vires on occasion, or inoperative for constitutional reasons.
The article also notes the impact of the decision on legislative drafting, making it allegedly less likely to be complicated and overly detailed.
The Uniform Law Conference of Canada has a current project to update the Uniform Interpretation Act. Should a new Uniform Act expressly deal with the use of legislative history by the courts, and if so, how?
[h/t to Sandra Petersson of the University of Alberta for pointing out the Wikiepedia main page entry.]