The two are believed to have been planning a suicide attack using explosives and a knife at the home of the prime minister on 10 Downing Street.
United Kingdom authorities think they've arrested two men who plotted to kill Prime Minister Theresa May after "bomb (ing) their way into" her official residence, the Guardian reported. Three of the perpetrators were known to security services, according to an internal review which said opportunities to stop the Manchester Arena bombing attack were missed by security services.
Officials said it was the 22nd foiled plot since March as hundreds of terrorist suspects remain under investigation.
They were arrested in raids by the Met's Counter Terrorism Command in London and Birmingham on November 28.
He has been charged with preparing acts of terrorism and will appear in court alongside Mohammed Aqib Imran, 21, who is accused of trying to join Islamic State.
Both men, who indicated that they would plead not guilty, were remanded in custody until their next court appearance on December 20.
The alleged plot was reportedly revealed by the head of Britain's M15 unit Andrew Parker, while briefing Cabinet ministers.
Naa'imur Rahman, of north London, has been charged with preparing to commit acts of terrorism.
News reports have claimed that MI5 has thwarted nine terrorist plots in the last 12 months.
So far, there have been no comments from 10 Downing Street.
After the meeting, the prime minister's spokesman said: "The prime minister led thanks to the tireless work of staff at MI5 to combat the unprecedented terrorist threat". Thirty-six people have died in four terror attacks in Britain this year.