Specifically that article is by Damian McBride, who was Gordon Brown's SPAD. It's continuation of a political brawl by means of a newspaper column. Not a very nice chap:

"On 11 April 2009, he resigned his position after it emerged on a political blog that he and another Labour Party advisor, Derek Draper, had exchanged emails discussing the possibility of disseminating rumours McBride had fabricated about the private lives of some Conservative Party politicians and their spouses. The emails from McBride had been sent from his No. 10 Downing Street email account."

Chris Dillow is a good read on this topic

http://stumblingandmumbling.typepad.com/stumbling_and_mumbli...

A web search is not meant to count as research, it is the equivalent of a library catalogue search. You're meant to follow the links and find out what is written on the subject. It is the internet equivalent of a literature study and as such a form or research. The assumption here is that the reader is intelligent enough to be able to separate authoritative sources from hearsay and agenda-based publications.

By the way, using terms like "no reputable journalist" is called "Master suppression technique" or "domination technique" [1]. It is detrimental to having a fact-based discussion and generally seen as a cop-out for those who don't have real arguments to add to the discussion.

[1] https://en.wikipedia.org/wiki/Master_suppression_technique