The second day of my holiday we visited Jerusalem. We started by walking from the Mount of Olives to the Western Wall, we paused at the place where Jesus is said to have wept over Jerusalem. (The view from there is the usual view you see BBC news reporters when they're reporting live from Jerusalem. I felt like pretending to be Orla Guerin and video myself but thought this was a bit silly)

We wandered down through the Kidron valley and eventually to the Western Wall. It was there that I made a Rabbi ritually unclean. It was the feast of Sukkot so the area around the western wall was jammed with people. I was being a bit of a tourist and gawking at what people were doing. To get to the wall I had to borrow a yarmelke to wear on my head. So now I look like an appropriately dressed tourist gawking at people. And it's then that I feel a vice like grip on my arm leading me towards the wall. There's a little old Rabbi (he looks just like you imagine him, only older and more wrinkly) leading me in the right direction. He shows me where to stick my piece of paper (Obama had done this a few months before me), how to correctly pray and the right words to say. (This is after all, one of the holiest places in Judaism) My sister questioned me before going about the validity of praying at the wall. "Does God hear your prayer there more than anywhere else?", I must admit my sister is smart. This was a good question. Which I mumbled something that sounded like "probably not".

But being the good blogger I am, I've done some research on the subject and the sages state that anyone who prays in the Temple in Jerusalem, “it is as if he has prayed before the throne of glory because the gate of heaven is situated there and it is open to hear prayer”. So, yes, God did hear my prayer more than somewhere else. Remember the Rabbis hand is still clamped to my wrist at this point. He leads me back through the nodding, muttering crowd and then pronounces a blessing over me. My going out, my coming in, my parents, my wife, children, synagogue, Rabbi, my work, my home, my door lintels... And instead of basking in this beautiful religious moment I'm stood there thinking "he shouldn't be touching me". According to Rabbinical law as a gay person I'm unclean. And no one should ever touch anything unclean because somehow the "goo" sticks on you and makes you unclean too. I was doing well for a mornings work. I'd spoofed Orla Guerin and made a rabbi unclean, what next for me?

We walked from the Western Wall to a little rooftop cafe called Papa Andreas. Gave an awesome view over the city. Great food at a reasonable price.

Our group leader, Garth Hewitt, got our attention and said a little about Mordechai Vanunu and then pointed to the next table and said "And that's him..."

Vanunu's name tickled a deep part of my brain, one of those names I recognise from human rights activism but can't pinpoint. Thankfully Garth had properly explained who he was for us all.

Vanunu is an Israeli former nuclear technician who revealed details of Israel's nuclear weapons programme (which they don't have) to the British press in 1986. He was subsequently kidnapped in Rome by Israeli agents and smuggled to Israel, where he was tried and convicted of treason.

Why kidnap and try someone for a nuclear programme that doesn't exist? Israel has never signed the non-proliferation treaty. As a result, it is not subject to inspections and the threat of sanctions by the United Nations nuclear watchdog, the International Atomic Energy Agency. Vanunu's evidence meant the rest of us could know how many warheads they've got (widely believed to be around 200-300 or so, compared to India and Pakistan having around 20 each).

Mordechai spent 18 years in prison, including more than 11 years in solitary confinement. Vanunu was released from prison in 2004, subject to a broad array of restrictions on his speech and movement. Since then he has been briefly arrested several times for violations of those restrictions, including giving various interviews to foreign journalists and attempting to leave Israel.

In 2007 Vanunu was sentenced to six months in prison for violating terms of his parole. The sentence was considered unusual even by the prosecution who expected a suspended sentence. In response, Amnesty International issued a press release on July 2, 2007, stating that "The organization considers Mordechai Vanunu to be a prisoner of conscience and calls for his immediate and unconditional release." Vanunu has been characterized by some as a whistleblower and by others as a traitor.

He was a charming man who was keen to share his story, answer our questions and get to know us. We then seemed to stalk him around Jerusalem over the next 24 hours and he answered our questions again.

If you want to write to him his address is:

Mordechai Vanunu
Salah Adin Post Office
PO Box 20102
East Jerusalem 91384
Israel