Tips on how to be a jihadi fighter given by al-Qaeda terrorist Omar Khyam to July 7 bomber Mohammed Sidique Khan were overheard by MI5.

The most important thing, Khyam tells Khan in their taped conversation, is always to follow orders and do what your emir (commander) says.

Khan had travelled to southern England from Yorkshire to seek advice from Khyam, from Crawley, who was arranging to take "brothers" with him to Pakistan.

Khyam says: "One thing I will advise you, yeah, is total obedience to whoever your emir is, whether he is Sunni, Arab Chechen, Saudi, British, total obedience.

"I don't know if you heard about the (unclear on tape). He disobeyed one order, (unclear) lies cut out his throat. I'll tell you up there you can get your head cut off."

The conversation on February 21, 2004, took place in Khyam's car which had been bugged by MI5.

Khan had met Khyam at a terrorist training camp in Pakistan the previous year and had meetings with him in February and March 2004.

Khyam was arrested on March 30, 2004, as his plans to bring terror to Britain were nearing fruition, and a week before the planned trip.

Some 16 months later, Khan - who had made two further trips to Pakistan - and three others blew themselves up on the London transport system, killing 52 people.

Khyam, 25, and two other Muslim men were jailed for life at the Old Bailey on Monday for plotting explosions with chemical fertiliser in the UK.

The recording and meetings were kept secret from the jury.

MI5 had dismissed Khan as a fraudulent fund-raiser and he was allowed to slip the net.

But a full transcript published on The Argus website today gives a fascinating insight into their dealings.

KHAN: Are you really a terrorist, eh?

KHYAM: They're working with us.

KHAN: You're serious, you are basically.

KHYAM: No, I'm not a terrorist but they are working through us.

KHAN: Who are? There's no one higher than you.

Talking of the intended trip, Khyam tells Khan: "This is a one-way ticket, Bruv.

"You are going to leave now you may as well rip the country apart economically as well.

"All the brothers are running scams and I advise you to do the same. You will probably walk away with twenty grand."

Khan asks if he can delay his trip because his wife is due to give birth.

KHAN: "The child is due on 25th of May. I'd like two, maybe three weeks after that, just so physically she's OK and the child's all right.

"That is the absolute latest to go. Is that OK?

KHYAM: "No problem, Bruv."