Ardent supporters can be a pest at times and this morning Peter Costello probably puts Glenn Milne in that category.

Over the years the Treasurer has basked in the praise of the punchy little columnist for The Australian but now that John Howard isn’t going anywhere, reminders of leadership contests to come are not what Mr Costello needs.

Milne’s column under the headline “Turnbull could sink” will be interpreted in Canberra as reflecting the views of a churlish Costello wishing failure upon his chief potential rival for the Liberal leadership.

The column itself suggests that Turnbull’s rapid elevation to Cabinet rank is the result not of merit but of Prime Ministerial patronage designed to ensure that Costello has a challenger of substance when the great man finally departs.

Heaven forbid but Turnbull recently even “chatted amiably with Janette Howard, the ultimate arbiter of who gets entry into Howard’s inner orbit.” Has the man who once declared that Howard was the “Prime Minister who broke the nation’s heart” over the republic got no shame?

For good measure Glenn has tossed in that best of all sources, the anonymous Liberal MP who declares that the PM will see the error of his ways when Turnbull starts getting on his nerves by starting to “claim credit for fixing the water crisis.”

Perhaps that is true but elsewhere the thrust of the column is that the water crisis will not be easily or quickly fixed as state Premiers bring forth their weasel words and protracted negotiations end up in the High Court.

A little each way commentary, of course, is not important when the main message is to leave the impression that a two-faced Howard is principally concerned with making future life difficult for your mate the Treasurer.

As Milne puts it: “Despite the Prime Minister’s public comments to the contrary, few in the Liberal caucus are in any doubt that Howard is constructing the Turnbull edifice as yet another bulwark against Costello …”