Gethin Lewis is busy clearing out his office. On the desk are strewn the press cuttings that reflect key events during his nine-year tenure as secretary of the National Union of Teachers in Wales.

By far the largest pile relates to Marje Evans, the now-retired south Wales headteacher accused, then vindicated, in a high-profile court case, of slapping a pupil.

Support for Mrs Evans from the NUT placed Mr Lewis firmly in the media spotlight. But the notorious trial was not the first time Mr Lewis attracted national media attention. As headteacher at Gabalfa primary school in Cardiff, he hit the headlines when he refused to kow-tow to the then Conservative government’s controversial Sats programme.

“I’m not opposed to tests - I’m on the Welsh Joint Education Committee’s examination and assessment committee - and I think that continuous assessment of a child’s progress is important,” he says.

“But I’m against labelling children, and that’s what Sats did. They reminded me of the 11-plus, where those that failed to make it to grammar school were consigned to the academic scrapheap.”

Tough though the clash with the government over Sats proved to be, he had already overcome a far bigger battle against testicular cancer, diagnosed in 1988.

“When the consultant asks you if you have put your affairs in order, it forces you to reconsider your priorities,” he confirms. “But my recovery period gave me plenty of time to reflect on the potential implications of Sats. So the decision to stand against them in 1991 was a considered one.”

Mr Lewis was born in the Swansea Valley on May 1, 1946, to a working class, Welsh-speaking family.

Aged seven, he moved with his family to Porthcawl, entering Nottage primary school as the establishment’s only monoglot.

By a quirk of fate, this was also where he obtained his first teaching post, in 1968. There to welcome him was his former class teacher, Miss Walters, who also happened to be the NUT representative.

“Had I not gone back to Nottage, I might not have started on my union career,” he muses.

Fellow union man Geraint Davies, secretary of teachers’ union the NASUWT Cymru, describes Mr Lewis as a man with strong opinions and dry humour.

“Gethin is always prepared to fight his corner, although on a personal level he is kind and considerate. We have crossed swords but that hasn’t stopped us sharing a pint or two over the years.”

Iwan Guy, acting director of the National Association of Head Teachers Cymru, respects Mr Lewis as a tough negotiator.

“He is a consummate professional, and disputes never spill over into personal relationships,” he says. “He was also very brave to stand up for what he believed in over Sats, even though that laid him open to criticism.”

Jane Davidson, the minister who banished Sats from Wales, wishes Mr Lewis well in retirement, but is hoping he will “find new ways of being involved in education in Wales”.

“I have always been impressed by Gethin Lewis’s commitment to the causes of education and devolution in Wales,” she says.

So far, his plans for the future include devoting more time to wife Gill, a fellow teacher, his three grown-up children, and grandchild William Gethin.

And, as a keen rugby supporter, he is the happy holder of two debenture seats at the Millennium Stadium.