In May, voters will go to the polls in Hampstead and Kilburn to decide their new MP. As part of a series of interviews with the contenders, Tim Lamden talks to the Liberal Democrat candidate.

In the midst of four months’ solitary confinement in a filthy Egyptian prison, the leafy north London constituency of Hampstead and Kilburn could not have been further from Maajid Nawaz’s reality.

As a 23-year-old student sent by his university to spend a year learning Arabic in the north African country, Mr Nawaz turned his attention to recruiting new members to Islamic extremist group Hizb ut-Tahrir (HT).

Mr Nawaz, who had been an HT member from the age of 16, was looking for ‘brothers’ to join his crusade to topple the then-president Hosni Mubarak and establish an Islamic caliphate, the same goal now achieved in large parts of Syria and Iraq by the nihilistic Islamic State.

He was quickly arrested by the Egyptian intelligence services and jailed for five years, alongside some of the country’s grisliest criminals.

Amnesty International adopted Mr Nawaz – who had promoted a non-violent Islamist doctrine – as a “prisoner of conscience” and upon his release and return to the UK in 2006, his journey away from Islamism was well underway.

In 2007, he left HT, which had largely abandoned him during his time in prison, and a year later he founded the world’s first counterterrorism think-tank, the Quilliam Foundation.

But Mr Nawaz’s transformation came at a huge personal cost.

Having lost five years of his liberty in a foreign country, he returned to a wife who was still an active HT member and did not recognise the man who had originally recruited her and her family as activists for the group.

The pair soon divorced and in the subsequent years Mr Nawaz has been denied regular contact with his son, a sensitive subject he is very reluctant to broach.

With the steady rise of militant Islam globally, Mr Nawaz has become a point of call for expert opinion on the fight against terror from major broadcasters both here and across the pond.

He’s released an autobiography and nearly 40,000 people follow his liberal philosophy on Twitter.

When it came to choosing a political party, the choice was obvious.

“I’m not a conservative, nor a socialist,” he said. “I’m a liberal, so it seemed the natural thing to do.”

As the Liberal Democrat parliamentary candidate for Great Britain’s most marginal seat, Mr Nawaz’s election campaign would be in the national spotlight regardless of his profile.

But he believes his life story is what makes this particular fight extraordinary.

“I think this campaign is about more than your ordinary campaign in Watford or Eastleigh,” he said.

“It will resonate across the nation and it should, because it’s about some of the biggest issues of our day. That’s why I’m standing for parliament.

“How great would it be to have the first parliamentarian in this country who has been a Bush era, ‘War on Terror’ political prisoner who speaks fluent Arabic.

“No other parliamentarian does, yet we’re all over the Middle East. I speak Urdu and therefore can communicate with the south Asian communities as well.

“My mother tongue is English and I will stand there in parliament as an example of how this society can embrace people who rejected it before.”

It was a feeling of rejection that pushed Mr Nawaz into radical Islam as a teenager.

He was born in Essex’s Southend-on-Sea in 1978 to an English-born mother of Pakistani origins whose family arranged for her to marry Mr Nawaz’s Pakistani father.

As young Asians on the streets of Essex in the early ‘90s, Mr Nawaz and his brother were terrorised by racist skinheads from notorious neo-Nazi group Combat 18.

It was this experience and discovering the horrors of the Bosnian Genocide in 1995, during which thousands of Muslims were massacred by Bosnian Serb forces, which pushed Mr Nawaz into the clutches of HT.

Today, his parents, who are now divorced, are supportive of his mission and were both present at his recent marriage to wife Rachel, a classically trained pianist from Tennessee, USA.

The couple live together in Camden but Mr Nawaz is unable to specify where exactly because of ongoing threats to his life from extremists.

The 37-year-old, who insists he has not lost his faith and remains a Muslim, has become conditioned to living life with risks.

“Human beings are wonderfully capable of adapting to situations,” he said.

As a man distinctly in tune with the Arab world, Mr Nawaz keeps a keen eye on the ongoing conflict between Israel and Hamas.

He supported the House of Commons motion to recognise a Palestinian state, insisting he backs a two-state solution “which includes a viable Palestinian state alongside a secure Israeli state”.

But for all his credentials, does he really believe he can be successful as the candidate for a party, wounded by coalition with the Conservatives, which is hovering at six per cent support in the polls?

“When you’re listening to LBC with Iain Dale, when you’re listening to Radio 4’s Any Questions?, when you’re watching Newsnight or when you’re reading The Times, which has profiled me, what you’re seeing is Maajid Nawaz, not six per cent Lib Dems,” he said.

“What I’m hoping is when you’re seeing [me in the press] you’re thinking, ‘My God, I’m concerned about these things, as he is, because I just voted religious and ethnic strife as one of the biggest issues in the country. Here’s a guy who’s addressing all this.’

“So what I’m hoping is that people will vote around issues in this constituency and not parties.

“That’s how we are going to try and win.”