Convicted Isis supporter Anjem Choudary will be in effect banned from any public statements after his release from prison this week, as British authorities seek to stop him from inciting support for terrorism.

British officials believe they have drafted conditions that will stop Choudary from repeating his method of drumming up support for extremism, which enabled him to escape prosecution for years even as his propaganda motivated at least 100 people to pursue terrorism.

He is scheduled for release from prison on Friday after serving half of the five-and-a-half-year sentence he received in 2016 for urging support for Isis and pledging allegiance to the terrorist group.

In prison, he was offered counselling to try to change the views that led to his conviction. It is not known if those efforts were successful, but his release halfway through his sentence shows that, despite his past pronouncements denouncing western authorities, he observed prison rules.

He will be released on licence, which allows British authorities, after consulting counter-terrorism investigators, to impose strict conditions restricting his freedoms while he completes his sentence in the community. MI5 and Scotland Yard’s counter-terrorism command believe Choudary still poses a danger.

He will need prior approval from his probation officer, which he is not expected to be given, to take part directly or indirectly in demonstrations, public meetings, social media chat groups, public statements to the media or anything that disseminates his views. UK and European counter-terrorism officials believe he encouraged more than 100 people into terrorism.

People connected to Choudary and his groups who turned to terrorism include Michael Adebolajo, one of the men who murdered the soldier Lee Rigby on a London street in 2013. He is also linked to foiled plots to kill in the UK more than a decade ago, encouraging youngsters to join Isis in Syria, leaving their families distraught, and allegedly inspiring violence across Europe.

Choudary will be banned from leaving London and using the internet without permission. He will be restricted to a single phone that can be inspected at any time.

He has been placed on a blacklist by the United Nations, meaning his assets are frozen and is banned from international travel.

Choudary was formally added to the terrorist sanctions list operated by the UN security council on Monday and to the British Treasury’s sanctions list for terrorist supporters on Tuesday.

Choudary was a key figure for a succession of extremist Islamist groups. He was dismissed as a clown by some, while helping motivate youngsters to turn to terrorism in Britain and Europe, and enjoyed frequent media appearances.

He was a key figure in al-Muhajiroun before it was banned under terrorism legislation and relaunched itself as al-Ghurabaa, which again was banned. Successor groups, such as Islam4Uk and Muslims Against Crusades, were also banned. He will not be allowed to associate with supporters of those groups on his release.

Choudary was convicted finally after telling supporters to obey Abu Bakr al-Baghdadi, the Isis leader, who is also known as a caliph, and travel to Syria to support Isis or “the caliphate”.

On the ninth anniversary of the London terror attacks – 7 July 2014 – Choudary and Rahman posted an oath of allegiance online under their kunyas or Islamic names, Abu Luqman, used by Choudary, and Abu Baraa, used by Rahman, on an extremist website.

Choudary’s influence was sufficiently widespread that the Dutch intelligence agency AIVD assessed him to be a key influence in the spread of the jihadi movement in the Netherlands.