The Freemasons have placed full-page advertisements in several national newspapers calling for an end to the "discrimination" against their members.
The United Grand Lodge of England (UGLE) said it welcomes individuals from all walks of life but that members are "undeservedly stigmatised".
It said it had written to the Equality and Human Rights Commission.
Recent news stories questioned the influence of Freemasons in policing and in parliament.
In an advert in the Times, the Daily Telegraph and the Guardian, the governing body of Freemasonry complains of the "gross misrepresentation" of its members.
Under the headline "Enough is enough", chief executive Dr David Staples said the organisation raised more than £33m for good causes last year.
He said people of any race, faith, age, class or political persuasion were welcome in the 300-year-old organisation.
The United Grand Lodge of England is restricted to men, although separate women-only lodges also exist.
Dr. Staples is correct. Freemasonry is not a sinister organisation, far from it. I laugh when Christians, who go to church and pretend to eat and drink the flesh and blood of a long-dead man, claim that Freemasonry is somehow unholy.