Scott Morrison and Mathias Cormann came out with a stupendous list of spending promises by Labor on Tuesday – the sort you usually bring out when things are getting really desperate in an election campaign.

But by the end of the press conference to announce this list, after being challenged on the numbers, the Treasurer was having to concede that "Bill Shorten's $66.87 billion great big budget black hole" might be just a teensy bit smaller.