At the time of the trial the judge Mr Justice Treacy referred the article to attorney general Dominic Grieve.
Grieve then referred the magazine to the CPS "for consideration of whether a reporting restrictions order in place at the time had been breached", the CPS said today.
According to the CPS an order was made under Section 82 of the Criminal Justice Act 2003 "prohibiting publication of certain assertions about the defendants". This order was "imposed by the Court of Appeal on 18 May 2011 and was continued at the commencement of the trial on 14 November 2011".
Today the CPS London Chief Crown Prosecutor Alison Saunders confirmed she had decided "that there is a realistic prospect of conviction" and that "the Attorney General has determined that it is in the public interest to proceed and he has given his consent to this prosecution".
She added that "where a charge is brought under Section 83 of the Criminal Justice Act 2003" against a newspaper or periodical then it is the proprietor, editor or publisher who may be liable for any alleged offence "and not the author".
"Accordingly, a summons against the publisher of the magazine, The Spectator (1828) Ltd, has been obtained from City of Westminster Magistrates' Court, and the first hearing will be on 7 June 2012."
The Spectator declined to comment.