Why government spend and waste so much on consultancies?

Comments on TOM DUSEVIC “Labor losing war on bureaucratic waste as consultants' bill hits $450m”, 10/11/2009, http://www.theaustralian.com.au/news/labor-losing-war-on-bureaucratic-waste-as-consultants-bill-hits-450m/story-e6frg6n6-1225795930232

The spending on consultancies should be considered together with spending on public servants to have the correct context, if what Mr Moran said was to be believed, that is "Some of the growth (in spending on consultants) would be represented by the strategic use of consultants to provide particular, scarce expertise for a number of high-priority projects," and "This is a consequence of new initiatives, which require a set of skills that haven't been required by the public service in the past."

The public services have so many people, why do they have those so called "new skills"?

What is the PS for, if they can't do what the government's new initiatives require of them?

There are so many excuses for doing any silly things using taxpayers' money!