An 'unconventional' interim Budget

Was Friday's Budget an act of constitutional impropriety, as the government's opponents have proclaimed, or was it justified, as its ministers insist?

With a speech that stretched over a hundred minutes the interim Finance Minister has announced major, new and sweeping policies that will have a significant impact on our people and economy. He called it an interim Budget but it definitely wasn’t. It was a full-fledged Budget. Not only does it bear no comparison to the interim Budgets delivered by Jaswant Singh in 2004, Pranab Mukherjee in 2009 and P. Chidambaram in 2014 but few full-fledged Budgets have been as ambitious as this one.  

So was this an act of constitutional impropriety, as the government’s opponents have loudly proclaimed, or was