When Gordon Brown’s most senior media adviser began drawing up a list of stories, innuendoes and smears for an aggressive new anti-Tory website in January, it must have seemed like the makings of the perfect foil for the Tory-dominated blogosphere.

With their growing readership, grassroots campaigns and loyal fans, right-leaning websites such as Guido Fawkes and ConservativeHome have long taunted Labour for its failure to harness the power of the internet.

So when Damian McBride, the Prime Minister’s head of strategy and planning and backroom powerbroker, began to pull together ideas for a “no fingerprints” internet initiative to be called Red Rag, there was no doubt that the Downing Street bruiser was in the mood for a fight.

The website had an editor — a little-known union official called Andrew Dodgshon, a website address and, crucially, a deep-pocketed backer: Charlie Whelan, the powerful political director of Unite, the union that is Labour’s biggest donor. The aim of Mr McBride and his allies was to “destabilise” the Tory Opposition in the run-up to the general election.

The website appears to have been modelled on Guido Fawkes, which is run by a libertarian former trader whose gossipy, campaigning style has generated a huge following in Westminster and beyond.

All Mr McBride’s team needed was something to write; although the truth, Mr McBride suggested at one point, could be subject to “poetic licence” for the greater good of Labour.

Egged on by Derek Draper, the former adviser to Lord Mandelson who runs an independent website for Labour supporters called LabourList, the pair set to work.

“For ease, I’ve written all the below as I’d write them for the site,” Mr McBride wrote in e-mails to Mr Draper and Mr Whelan, making clear that he was planning the first suggestion of many. What followed were five deliberately provocative and unfounded stories that they believed would get the site noticed.

The first, about a gay Tory MP promoting his companion’s business interests in the Commons, was said by Mr McBride to be a “solid investigative story”. It suggested that the unnamed MP had used his position in the Commons to advance the personal interests of his companion. The other four were “gossipy and mainly intended to destabilise the Tories”.

This began with a suggestion to challenge Mr Cameron to publish his “full financial and medical records”, hinting that he may have suffered from a sexually transmitted disease. This would appear to be prompted by an interview given by the Tory leader to a magazine revealing that he had once attended an STD clinic in Oxford.

One suggested that Mr Osborne had sex and took drugs with a prostitute and that a former girlfriend had pictures of him in women’s underwear. It also suggested writing a story saying that Mr Osborne had “blacked up” his face.

The third suggestion — which particularly bruised the Conservatives — was to use the website to make allegations about Frances Osborne, the wife of the Shadow Chancellor.

Times Recommends

• UK regional accents thrive against the odds
• ‘Scarecrow’ wind farms put rare birds to flight
• What an anti-climax: G-spot is a myth