The Advertising Standards Authority has responded to claims by a religious blogger that correspondence it sent him requesting he comply with an investigation into a Coalition for Marriage advert amounted to ‘persecution’.

The blogger refers to himself in the third person and adopts the pseudonym Archbishop Cranmer, occasionally taking on the identity of the 16th century cleric to comment on current affairs.

The ASA is investigating an advert by the Coalition for Marriage which complainants believe was offensive, homophobic or misleading. The Cranmer blog, among others, ran the advert online.

The advert showed pictures of couples on their wedding days, the words “I do”, the statement “70% of people say keep marriage as it is (Source: ComRes poll for Catholic Voices)”, and the words “Please sign the petition”, with a link to the Coalition for Marriage website.

Last week, the widely-read Christian blogger said the ASA had “persecuted” him in correspondence containing “all manner of official papers, formal documentation and threatening notices” which “demanded” answers to a number of questions about his decision to run the advert.

The blogger reprinted parts of the ASA’s correspondence in which it said: “We require you to explain your rationale for the ad” and “robust documentary evidence to back the claims and a clear explanation from you of its relevance and why you think it substantiates the claims” as part of the investigation into the Coalition for Marriage advert.

He added that gays could have emailed him the complaint “and we could all have had a jolly good chinwag about the whole thing”.

“Instead, they called in the Gestapo to censor the assertion that marriage is a life-long union between one man and one woman, in accordance with the teaching of the Established Church, the beliefs of its Supreme Governor, and the law of the land. But to say so is now, apparently, ‘offensive and homophobic’.”

The ASA said today: “One of the bloggers on whose blog the ads appeared has raised concerns about us contacting him as part of our investigation. We have long found it useful to ask, in confidence, publishers of ads subject to ‘offence’ complaints for their views, because they can give us a valuable insight into whether or not their readers are likely to be offended. They are not the subject of our investigation, as we have made clear to them in this case, and they are not compelled to respond.

It added: “We cannot comment further on our ongoing investigation before we reach a decision, but we will very carefully assess the issues at hand before we publish our findings.”

Cranmer said today it was “untrue” that the ASA had “made it clear” he was not compelled to respond to the request for information, reproducing more of the correspondence and saying it was “fatuous” to question whether a blog would publish material its readers would find offensive.

He accused the ASA of “obfuscating and issuing misleading statements”, adding: “And if they are not purposely misleading, they are mightily deluded in the extent to which their polite requests for ‘valuable insight’ might be construed as aggressive demands and threats.”

He added: “It is categorically not stated anywhere that he is ‘not compelled to respond’; indeed, there are so many suggestions to the contrary that the ASA appear not merely to be obfuscating with semantics, but lying.”

Cranmner had already sent an initial response to the ASA on Monday, publishing it in full online.

It was prefaced with a request for readers to send him money as it had distracted him over the weekend.

Still in character as the deceased archbishop, the response asked for the ASA’s compassion during its investigation as the blogger had “endured some appalling persecution and had the most unpleasant encounters with smouldering faggots” in the past.

The reference to the real Archbishop Cranmer’s burning at the stake in 1556 and outmoded use of ‘faggot’ as a term for firewood delighted readers who described it as “beautiful” and “your best ever” and proclaimed the blogger a “master” of the English language.

Cranmer pointed out that the advert was carried on ConservativeHome and the Guido Fawkes blog but they were not being similarly consulted, asking: “One presumes it has nothing to do with the fact that ConservativeHome is generously underpinned by Lord Ashcroft’s £millions, or that Guido Fawkes isn’t without the means to call in the lawyers or lacking the rottweiler tendency to tell you where to go.

“Why have you chosen to victimise and harass the weakest, lowliest, and most utterly insignificant of the blogs which carried this advertisement?”

In addition to the ten complaints that the advert was “offensive and homophobic”, the ASA received two dozen complaints that the 70 percent figure used to encourage people to sign the anti-gay marriage petition was misleading.

The figure came from a ComRes/Catholic Voices poll which asked whether the marriage should “continue to be defined as a lifelong commitment between a man and a woman”.

When the results were used to oppose government plans for civil marriage equality, the survey was criticised for not directly mentioning marriage for gay couples or detailing what any change to the definition would entail.

Catholic Voices acknowledged that the figure was out of line with other polls, saying its purpose “was not to gauge support for same-sex marriage” but to “assess support for the state promoting the existing understanding of marriage”.

Though several polls which asked people about the issue directly had shown more people in favour of equal marriage rights than opposed, Catholic Voices defended the 70 percent figure, saying “many people did not grasp” what was being asked by other polling agencies, including YouGov, which found 43 percent support and ICM, which found 45 percent support when asking directly.

Catholic Voices argued that if the public “realised” marriage equality involved a redefinition of the institution, the results of other polls would start to fall into line with theirs.

The ASA continues to investigate whether the way in which the Coalition for Marriage used the figure to promote its petition was misleading.