The radical cleric Anjem Choudary has been charged with inviting support for the terrorist group Isis.
Choudary, 48, of, Ilford, east London, has been charged with committing the alleged offence between 29 June last year and 6 March.
Mohammed Rahman, 32, of Whitechapel, east London, has been charged with committing the same alleged offence in the same time frame.
They are accused with inviting support for the banned terrorist organisation through lectures which were published online.
The Met Police have said both men have been detained in custody and are due to appear at Westminster Magistrates' Court at 2pm today.
A police spokesman said the men were arrested by the Met's Counter-Terrorism Command (SO15) on suspicion of being members of the proscribed organisation on 25 September last year.
They have remained on police bail throughout the investigation.
Both Choudary and Rahman have been charged under the Terrorism Act 2000.
Sue Hemming, Head of Special Crime and Counter Terrorism at the Crown Prosecution Service, said: “Following an investigation by the Metropolitan Police’s Counter Terrorism Command, we have today authorised charges against Anjem Choudary and Mohammed Mizanur Rahman.
“We have concluded that there is sufficient evidence and it is in the public interest to prosecute Anjem Choudary and Mohammed Rahman for inviting support for ISIL, a proscribed terrorist organisation, between 29 June 2014 and 6 March this year.
"Each man is charged with one offence contrary to section 12 of the Terrorism Act 2000.
“It is alleged that Anjem Choudary and Mohammed Rahman invited support for ISIS in individual lectures which were subsequently published online.
“The decision to prosecute was taken in accordance with the Code for Crown Prosecutors.
"Criminal proceedings have now commenced and both men have the right to a fair trial."
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