The Parsons Green bomber was moved by “anger and hatred” when he planted 400g of explosives on a packed Tube train, jurors have been told.

Ahmed Hassan, 18, told his mentor Katie Cable that it was his “duty to hate Britain”, the country he blamed for the death of his father in Iraq, the court heard.

He had also told Home Office officials he had been “trained to kill” by Islamic State when he claimed asylum in 2016.

But in his evidence to the Old Bailey, he said that was a lie and he only wanted to cause a fire, and not an explosion, when he planted a homemade device last September.

In her closing speech, prosecutor Alison Morgan said: “He may have been troubled by events in his past. He may well be motivated by circumstances he may now not admit to you.

“What he did that day was an act of anger and hatred designed to cause death and destruction of property.”

She said Hassan “left nothing to chance in the preparation of this attack”.

“It is a matter of luck that there was not a full explosion that day, not because of any deliberate intention on the part of the defendant to cause just a fire.”

Ms Morgan replayed CCTV footage of the fireball ripping through the carriage on September 15 last year.

She said passengers had been “terrified”, with some suffering serious injury.

She asked jurors to imagine what would have happened if 400g of TATP had fully exploded, sending 2.2kg of screwdrivers, knives, nuts and bolts flying at high velocity.

“Whatever story he tells you in the witness box, the fact that he was angry with this country was clear to those who met him, especially Ms Cable … he described it as his duty or right to hate this country and he blamed this country for the death of his father.”

She suggested Hassan lied to the jury when he claimed it was all part of a fantasy and an act of “boredom and attention-seeking”.

Ms Morgan said: “He may well have lied to all those people for two years but he may well also be lying to you.

“Lying to you about the truth of his past with Islamic State for the obvious reason that if he was trained to kill by IS that would tell you something about his mindset and who he really is and where he has really come from.

“You can be sure it was not an act of attention-seeking or boredom. This was someone who wanted to cause death and damage and make good his escape.”

Ms Morgan said Hassan was “calculated and clever” in all his preparations.

When he looked up the news on the BBC website afterwards, Hassan told jurors he was reassured it was a “minor incident”.

But Ms Morgan said he will have learned that he had “failed” in his intention.

Hassan has denied attempted murder and using the chemical compound TATP to cause an explosion that was likely to endanger life.

Ahmed Hassan at Wimbledon Station before the Parsons Green bomb was detonated  (Met Police/PA)
Ahmed Hassan at Wimbledon Station before the Parsons Green bomb was detonated (Met Police/PA)

The teenager’s defence barrister said those who knew him saw a “sincere, positive boy”.

Tim Moloney QC told jurors staff at Barnardo’s had said he was a “very polite” young person “seeking help, looking forward to the future”.

Rather than setting out to commit acts of terror, Hassan went from being a “troubled young man” to doing well at college, he said.

Even as late as June 2017, he was busy researching potential university places at Kingston and Royal Holloway.

Mr Moloney said: “It seems to me the prosecution suggest there may be truth that maybe he was with IS and it’s possible we may never know.

“That’s not good enough for me. We say that if he was with Isis (another name for Islamic State), would he have said that and raised that potential with the Home Office and draw attention to himself in that way?

“If he was with Isis he would have had many opportunities to do what he wanted. Making TATP is a really straightforward process that can be done in a day.

“You have to judge this case on the evidence and nothing else – not speculation, fear or emotion.”