The campaign is called "They're watching you" and alerts the public to growing state infringements of civil liberties.
It attempts to tap into the wave of concern, highlighted by many national newspapers, about the government's moves to rush through new powers in the name of national security. They include new imprisonment for terrorism, wider surveillance and the introduction of ID cards.
Liberty is traditionally associated with niche issues affecting small groups of people, such as asylum seekers, but it is keen to raise awareness of the wider work that it does.
The insert targets men and women aged 35-50 who are "well educated" and "interested in the world around them".
In a move to test the market for more right-wing libertarian support, the leaflets appeared in The Spectator, as well as more traditional left-of-centre publications such as The Guardian and New Statesman.
Steven Montgomery, director of development at Liberty: said: "We wanted to test to see what sort of support we could get among the more right-wing section of society."
The campaign also represents a radical shift in the use of images. London-based agency Bluefrog was hired to deliver a brief to use strong images that reflect the wider work that the charity does.
Using more "punchy narrative" text than is traditionally associated with the charity, the insert is described as a move to test different audiences with new campaigns.
It had an initial print run of 250,000 and is said to have been successful in terms of the number of people signing up to be members, but also in terms of angry responses from the public.
A longer version of this article first appeared in Third Sector magazine.
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