LONDON (AP) — Britain's Freemasons placed ads in major newspapers Thursday, saying they are being unfairly stigmatized after reports of clandestine lodges for lawmakers and journalists hinted at centuries-old allegations of secret conspiracies.

The United Grand Lodge of England, which describes itself as a fraternal organization with charitable aims, published the ad under the headline "Enough is Enough," saying that Freemasons are the victims of "ongoing gross misrepresentation." The advertisements appeared in newspapers including the Daily Telegraph and the Times.

"Our members shouldn't have to feel undeservedly stigmatized," the ad said. "No other organization would stand for this and nor shall we."

The Freemasons, who claim the likes of George Washington and Benjamin Franklin as members, have been the subject of conspiracy theories since the fraternal organization was founded some 300 years ago. Pope Clement XII condemned freemasons in 1738 and a committee of Britain's parliament investigated the role of freemasons in public life as recently as 1999.

The Guardian newspaper stoked those fears on Monday, when it reported that two lodges for members of Parliament and political journalists "are continuing to operate secretly it Westminster."

David Staples, CEO of the United Grand Lodge, said the treatment of the organization amounts to discrimination and he has written to Britain's Equality and Human Rights Commission about the matter.

But Staples also said he understands that people may have questions "about who we are and what we do," and Freemasons will hold open houses and question-and-answer sessions around the country in the coming months. He says the lodge raised more than 33 million pounds ($46 million) for good causes last year.

Freemasonry is believed to have originated in England and Scotland in the Middle Ages as a trade organization for stone masons engaged in the building the great cathedrals of Europe. But it lived on as a social organization, and over time the fraternity spread throughout the world, together with its secret ceremonies and rituals.

Its clandestine character and use of elaborate use of symbols has also led to distrust, says Andreas Onnerfors, author of "Freemasonry: A Very Short Introduction." Onnerfors wrote that the public's view of freemasonry generally falls into one of two camps: idealization or distrust.

One strand promotes the idea that the purpose of freemasonry is to "develop a charitable responsibility for humanity as a whole," while the other suggests that the group "interferes in significant sectors of society."

Onnerfors said that recent upheaval over Britain's decision to leave the European Union has created political unease that has allowed conspiracy theories to thrive, together with worries that secret entities have a hand in governing.

"The entire issue of Brexit has released existential fears about the position of Britain in Europe and the world," said Onnerfors, an associate professor at the University of Gothenborg in Sweden. "You have that fear of where politics is going."

But Thursday's ad seemed to offer a new page — with Staples taking to the news channels and other media to argue it was a fraternal group like any other.

"I appreciate that you may have questions about who we are and what we do, so why not ask those who know?" he said.