‘Sister’ Ruth Augustus, 72, was found guilty of six counts of hoaxes involving noxious substances and was handed a two-year community order at the Old Bailey.
She will also be required to undertake treatment for mental health problems.
The letters were intercepted at an east London mail screening centre, one of which was addressed to Clegg. Written on the envelope was ‘devil worshipping’, ‘freemason’, and ‘sex with 30 plus women’, the court heard.
Augustus, from Cricketfield Road, Lower Clapton, admitted to sending the letters but claimed that police had planted the white powder in them.
Other intended recipients of the letters included House of Lords members Baroness Kennedy and Baroness Scotland, and MP Edward Leigh.
When questioned over why she had sent a letter to Clegg, Augustus said that it was because he “lied about the tuition fees” and was responsible for “keeping those Tory millionaires and rats in government.”
She added: “[Clegg] boasted about all the women he’s had sex with. He’s an atheist singing hymns in the Albert Hall.”
Augustus, who previously spent 12 years travelling around the world with a three foot statue of the Virgin Mary, seems to be no stranger to controversy.
In 2002 Time magazine reported that Augustus was arrested at a gay pride march in Croatia for shouting obscenities at participants.
Four years later she was fined for shouting racist abuse at women in Burkhas on Oxford Street.
The Catholic Church has previously urged people to steer clear of Augustus, following previous convictions of religious harassment.
A spokesperson for the Church told Eastlondonlines: “She is not a member of any recognized order, nor is she under any authority from us.”
The judge, Mr Justice Saunders, told Augustus: “Had [the intended recipients] opened the letters and found the powder there can be no doubt it would have been a terrifying experience for them, not knowing what the powder was contained in those envelopes.”
He said that ordinarily Augustus would face a prison sentence for her actions, but was spared jail as she suffers from a persistent delusional disorder that can be treated within the community.
Following the sentencing, Augustus shouted from the dock that the court was run by “devil-worshipping Freemasons, Nazis who break the law at huge expense.”