Theresa May
Theresa MayReuters

An Islamic State (ISIS) fanatic who plotted to kill British Prime Minister Theresa May in a suicide attack planned to “take her head off”, a court heard Tuesday, according to the Press Association.

Naa’imur Zakariyah Rahman, 20, allegedly wanted to make “big news” by storming 10 Downing Street with explosives and a knife as May talked to the press outside.

He was encouraged by an uncle who joined ISIS in Syria and was killed in a drone strike, the Old Bailey heard.

Rahman’s intentions were foiled after he revealed his plans to MI5 agents, posing as ISIS operatives in Telegram chat, according to the report.

The person who he was put in contact with to provide the bomb was really an undercover police officer.

News of the foiled terror plot to assassinate May was first made public last December, after two Muslim men were arrested on suspicion of planning to attack 10 Downing Street, the location of the Prime Minister’s office, with an improvised bomb, suicide vest and knives.

Investigators said the pair wanted to detonate a bomb disguised as a bag. They would then attempt to kill May armed with a suicide vest, pepper spray and knife in the chaotic aftermath.

In addition to Rahman, a second suspect was identified as Mohammed Aqib Imran.

According to Tuesday’s report, the prosecutor read out a Telegram chat in which Rahman was allegedly snared by an MI5 agent posing as a fake Amir.

In September last year, Rahman said, “Can you put me in a sleeper cell ASAP? I want to do a suicide bomb on Parliament. I want to attempt to kill Theresa May.”

He went on, “My objective is to take out my target. Nothing less than the death of the leaders of Parliament.”

Rahman has denied two counts of preparing terrorist acts. Imran has pleaded not guilty to preparing terrorist acts and possessing a terrorist document on his Kindle entitled How To Survive In The West – A Mujahid’s Guide 2015.

Britain has suffered several terrorist attacks in recent years, including four deadly attacks last year that killed 36 people.

Earlier this month, an alleged ISIS supporter who encouraged attacks on four-year-old Prince George of Britain admitted to a string of terror offenses.

Husnain Rashid, who previously insisted had had done nothing wrong, switched his plea to guilty on four counts of preparing terrorist acts and encouraging terrorism due to the "overwhelming weight of evidence".

Rashid, 32, a former teacher at a mosque in northwestern England, was accused of using the Telegram messaging site to encourage "lone wolf" attacks and to provide advice on the use of bombs, chemicals and knives.

MI5 chief Andrew Parker warned several weeks ago that ISIS jihadists are plotting “devastating and more complex attacks” and called for a close security partnership between Britain and the European Union.