Hewett was travelling with former Australian Democrats leader Natasha Stott Despoja and they were hoping to draw Australians' attention to the awful human tragedy unfolding in this drought-affected land.

Late one afternoon, they drove to a village school where one of Oxfam's partner organisations had installed a water pump.

They were met by the village chief, a tall, dignified man. ''He explained they had nothing to eat,'' Hewett recalls. The chief told them the only food available was a little cereal, and the leaves from the trees. Hewett and Stott Despoja were ''the biggest show in town'' that afternoon. It was school holidays and they were soon surrounded by the children of the village. None had eaten that day.

Despite the despair, Hewett was also taken by the way the village head was dealing with the situation. ''He had that dignity still, and was trying to find a way ahead.''

The encounter illustrates powerfully the two aspects of his work with Oxfam - the distressing situations that motivate the organisation's work, and the strength of the human spirit that can still shine through.

It is this combination that he has seen often during his two decades with the organisation, the past 11 years as its Australian executive director.

At the end of the year, Hewett is stepping down from the post, feeling that the time is right for a change. ''The job is an all-consuming one. It's a wonderful job,'' he says. ''But you get to a point where it's good for the organisation to have some change, and it's probably good for yourself as well, no matter how much you continue to enjoy it.''

Stott Despoja recalls that afternoon at the village in Burkina Faso as having a profound impact on both of them. She was talking to children the same age as her own and asking them if they had eaten that day. ''They look at you with incredulity,'' she says.

Hewett will be a great loss to Oxfam, Stott Despoja says. She has had a long association with him, particularly when she was in the Senate with a responsibility for human rights and foreign affairs.

''I've always admired the unassuming way that he has approached his work and his tasks,'' she says. ''He's been one of the best, most well-informed individuals in this space.''

That Hewett wins such praise and has been such a good fit for Oxfam is perhaps not surprising, for in many ways it is a role for which he was made. The Melbourne-born son of an Australian POW and British war bride acknowledges he has been lucky enough to live his politics through his work.

This was a path he started on while still a teenager. Secondary school was at Melbourne High, where he soon found an outlet for his social conscience.

''It was the time of Vietnam, and I'm part of that generation, in a sense,'' says Hewett. ''I got involved relatively young as a 15, 16-year-old. My first demonstration I went to was the first moratorium: May 8, 1970. I think I had an English lit exam that morning.''

Hewett found there were fellow students who were like-minded. ''I wasn't alone. It really was the spirit of the times. I helped form a secondary students' union and that in a sense was taking some of the spirit of the times into the classroom.''

Melbourne High, he recalls, was a fairly conservative and traditional place, especially during his first couple of years there. Things soon changed.

In 1971, in his final year, there was a teachers' strike at the school over government plans to reform the then Teachers Tribunal. Hewett recalls Melbourne High was, in part, targeted by the teachers' union because the then education minister, Lindsay Thompson, had taught there. Most teachers at the school were out on strike for five or six weeks.

Hewett had his first exposure to the media when he found himself in front of cameras doing television interviews in support of the teachers.

Without their teachers, Hewett and other students set some informal classes. This self-help approach appears to have paid off. At a recent school reunion, it emerged the school's academic record had actually picked up that year.

Australia's engagement in Vietnam and conscription of 21-year-old males was a constant political theme in his life, even as Gough Whitlam's Labor Party was gathering momentum in its push to power that would mean an end to the involvement in the war.

Even though he was only 18, Hewett had made up his mind to resist the draft. He was on a school trip to Adelaide, where his father lived (his parents separated when he was four). He had had little contact with his father - ''an RSL type'' - but decided to use the visit to tell him of his decision.

''I'd resolved that I was going to tell him I was going to resist the draft and publicly do so. I really wasn't sure what the reaction was going to be. And he gave me a hug. So he'd changed his view, which was a great surprise. I really wasn't quite sure how he was going to jump.''

Hewett did well enough to make it into arts at Melbourne University. He became involved in student politics, becoming vice-president of the Student Representative Council and an organiser for the Australian Union of Students. He also worked on the university newspaper Farrago.

And study? ''It wasn't really a priority,'' he explains. It's something he regrets.

He has a love of reading about politics and history. ''I think just having a more structured approach to both those two areas of life and of study would have been beneficial.''

Nevertheless, Hewett's innate abilities as an organiser/activist continued to come to the fore. He worked for the peace movement in Melbourne, and then People for Nuclear Disarmament, where he organised two of the big Palm Sunday rallies.

He headed to Europe, first to the Cold War and a divided Berlin, where he attended the European nuclear disarmament conference, which included guests such as E. P. Thompson, the revered anti-nuclear intellectual and campaigner. He ended up in Britain, landing what would be a personally pivotal job for the Campaign for Nuclear Disarmament, working with trade unions.

The group decided to organise a protest in Barrow-in-Furness in the north-west of England, where the local shipyards built part of the Trident nuclear submarines and employed a third of the local workforce. Hewett had the hardest of messages to sell.

But he took a lateral approach, working with the local trade unions to develop a committee to find alternative employment. Between 25,000 and 30,000 protesters arrived in Barrow-in-Furness. ''But instead of being a point of confrontation, it became a point of, in a sense, collaboration,'' Hewett says. The key was recognising the community's right to a decent job.

Other jobs included time with the Child Poverty Action Group during the Thatcher years, keeping the child benefit universal.

He returned to Australia and after a brief stint with the union movement, heard about a job at Community Aid Abroad. The group would merge with the Australian Freedom from Hunger Campaign to eventually become Oxfam Australia. (Oxfam began in England in 1942 as the Committee for Famine Relief, which aimed to get food to starving women and children in enemy-occupied Greece. Its central aim today is the elimination of poverty.)

Hewett has been with Oxfam during some of the region's and the world's biggest humanitarian disasters, including the 1999 crisis in Timor, the 2004 Boxing Day tsunami and, lately, the African food crises.

There has been a growing debate about how aid organisations operate, including the threshold question: can they sometimes do more harm than good?

Hewett acknowledges that can be the reality. For example, a few years ago in West Africa sexual abuse of local people by staff of humanitarian agencies was a problem.

''There is a real danger of harm being caused - those who have experienced major humanitarian disasters or crises are frequently traumatised and highly vulnerable,'' says Hewett.

Oxfam, he says, has responded with a Do No Harm approach, and seeks to amplify the voices of the least powerful, such as women, members of ethnic or religious minorities, and indigenous peoples.

One of the newest and difficult challenges aid organisations face is their involvement in middle-income countries, where the majority of the world's poor live.

They include nations such as India where 400 million people are still classified as poor.

If the government can provide the services these people need, what role does an aid organisation have?

Hewett has seen the work of a partner group JOSH - the Joint Operation for Self-Help - which is concerned with India meeting the constitutional right to education. ''And they were succeeding. But they didn't provide a single classroom, train a single teacher, provide a textbook, or anything like that.

''What they did was mobilise the community to demand that of government officials and members of parliament and members of councils.''

He went to an open air session where about 250 people, mostly women, were encouraged to put forward their concerns and to develop what was effectively a log of claims for coming council elections.

Overwhelmingly, the log of claims was what they wanted for their daughters: desks, chairs and textbooks but also single-sex toilets at schools. ''Basically, their approach is working.''

While Hewett has headed a big organisation, he is also acutely aware of the critical role played by supporters in the community.

He recently attended a farewell function in Adelaide, where one woman who spoke had been involved with Oxfam for 35 years.

''I know she wasn't alone in that group,'' he says.

''Oxfam supporters are deeply engaged, deeply committed. They will hold you to account. Sometimes that can lead to difficulties, but it's great.

''They own the organisation, and they have a trust, but they also want that trust repaid, and I think that's totally legitimate.''

Shane Green is a senior writer.