Burnt out? Fancy waving goodbye to your whiteboard and spending a bit more time with your rose beds? Well, says Tony Blair, you’ll just have to wait.

For an ageing profession that has faced unprecedented change over the past 20 years, confirmation that the Government plans to raise the retirement age from 60 to 65 by 2006 has induced a wave of hysteria and despair.

The publication of last year’s retirement and pensions Green Paper was prompted by the need to implement by 2006 a European directive on people’s right to work until 65. But since the initial outcry, the Government has been at pains to stress that nobody will be prevented from retiring before 65. Teachers will be able to retire on partially reduced benefits - and there’s the rub - with the detail to be thrashed out over the coming months.

Many teachers are more than ready to quit by the time they are 60. They feel drained, and many want to pursue other interests while they have physical and mental health. But some, albeit a small minority, wouldn’t dream of doing anything else, and in their senior years still prefer working in the classroom to putting their feet up, walking the dogs or honing their putting technique. The Association of Teachers and Lecturers, for example, has 630 members working beyond the age of 65, 90 of them full-time.

Henderson Clarke is 69 and in many respects the work he is doing now is the most fruitful of his career, the culmination of a lifetime of teaching. Far from coasting through his senior years, he has a frontline senior management job in a large and startlingly successful multicultural comprehensive where 80 per cent of pupils are from ethnic minorities, in the London borough of Ealing.

Mr Clarke is head of ethnic minority achievement at Cardinal Wiseman, a Roman Catholic technology and arts college for around 1,800 students aged 11 to 18. He travels from his home in Winchester to be at the school by 7am, where pupils are already waiting for him. He has a roving brief, working where he is most needed. He acts as mentor and counsellor to children with problems, tutors those with language difficulties, and helps sixth-formers fill in their university applications and prepares them for interviews. He tutors small A-level and GCSE groups that cannot be squeezed into the timetable. As a black man with outstanding skills in behaviour management, he troubleshoots behavioural problems throughout the school, modelling the teaching of black boys to other staff.

Mr Clarke says he never tires. “I get up every morning without the slightest problem.” Teaching to him is “like drugs”: he cannot get enough of seeing children motivated and achieving. “I cannot imagine I will ever give it up. If I stayed at home I would fossilise. My family (he has a wife and three sons, all university graduates, two of them dentists, the other successful in the music business) say I work too hard, but if I stayed at home they’d only find me jobs to do. I’d rather be at the Wiseman than painting windows at home or digging the garden any day.”

Last summer the Wiseman achieved a show-stopping A*-C pass rate of 93 per cent at GCSE, an awesome increase on the 34 per cent of seven years ago, when the current head, Paul Patrick, took over. He says Mr Clarke has been a major factor in this success, playing a key role in supporting borderline students, raising their game, achievement and aspirations. Mr Clarke, he adds, is the “father of the house”, a man of huge moral integrity. “He is honest, kind and considerate,” says Mr Patrick. “He is a good listener and never raises his voice. I trust him implicitly to give an accurate and candid view, and the students think he’s fantastic. If they want help they go to him. He keeps his promises. He is proof that you don’t need to be on the scrapheap at 60 or 65. Age doesn’t matter to me. If somebody is good, they are good whether they are 70 or 24.”

Mr Clarke worked as a section 11 ethnic minorities teacher at Cardinal Wiseman until he was 65, when the local authority decided he would have to come off the payroll. “He was too good to lose,” says Mr Patrick, “so the school employed him directly on a one-year renewable contract.”

Mr Clarke keeps himself fit. He is in the gym every week and sticks to a careful diet, but it is working with young people that sustains him. “I don’t have problems with the children. I don’t shout or rave or rant, I just talk to them. I explain things in simple ways. They know I am on their side. Refugee children come to my room to have lunch and talk. Their experience is humbling.

“Children want to talk, they want to succeed. People say black boys do not succeed, but they do here; they cry if they don’t do well. We raise standards through the quality of our relationships. Many teachers think children are heavy, that it’s all about pressure. They don’t see the children as giving anything. We have special, brilliant children here.

“Teachers take themselves too seriously and wear themselves out on things that don’t matter. But young people revitalise you. If you want to stay young, listen to their conversations. Groups of tearaways come to my room after school to play Scrabble. If I’m away they want to know where I am.

When the exams are coming up I never leave school before dark because they want you to be there.”

Mr Clarke, the son of an engineer, was educated in a boys’ fee-paying school in Barbados and studied classics at Durham University. He went back to the West Indies after graduating to teach classics in a school in Jamaica, in the middle of a sugar plantation, and spent four happy years there with a “maverick” head who wasn’t a particularly good leader but was a great classicist and who “treated me like a son”.

He came back to England to train as a computer programmer but when marriage and children came along he was drawn back into teaching. He was stung, he says, by the attitude in England that black families did not support their children in education. He took this to heart, wanting to do the very best for his two sons, then aged four and five, and signed on at the Froebel Institute in south-west London to train in teaching and child development.

After several teaching posts and a primary deputy headship he moved into an advisory role for the Inner London Education Authority, working on pioneering projects in Islington and Lambeth on primarysecondary transfer and with ethnic minorities, finally moving to Cambridge aged 56 to be a school inspector.

At 60, he decided he wanted to spend his last few years back in the classroom and so looked for a post in a London secondary. There was no shortage of offers. Cardinal Wiseman had endemic problems with black teenage boys and gangs that “terrorised the school” and the former head was anxious to get a black teacher on board. Mr Clarke obliged, but it was hardly a gentle slide into retirement. He became hooked, and when Mr Patrick took over and the school began its sharp climb to success, he stayed. “Every day gets better and better,” he says. “You can see it in the children’s eyes.”

David Goldsmith, 76, lives in a very different world but shares a hardened addiction to teaching. Despite his seniority, he still spends four days a week teaching maths at Lord Wandsworth college in Hampshire, an independent school that boasts the England World Cup rugby star Jonny Wilkinson among its old boys, and every Friday teaching maths at Surrey college, a crammer near Guildford.

Mr Goldsmith spent most of his working life at Radley college, the all-boys public school near Oxford, as housemaster and sub-warden (deputy head), then left 10 years before he was due to retire to take up the headship of Cokethorpe, a small independent secondary.

But when he stood down aged 62, there was no question of his leaving the profession. He couldn’t wait to get back into the classroom. Which is where he still is. As a head, he still taught 15 periods a week and introduced classical civilisation to the school, which he also taught, and until the age of 67 had always coached games. Now he dedicates his time to maths, his first love, and to A-level maths examining for the OCR exam board.

“I enjoy the challenge of teaching and I love my subject and I think my teaching continues to improve. I have certainly mellowed a bit. I’m better at explaining things. Every example I give adds to my stock of knowledge and I learn from pupils as well.

“I love teaching but I hate education with a capital E. I don’t plan lessons, it’s all in my head; if it’s all written down it becomes too rigid and then you can’t be flexible or react to the moment. I know the days when it’s no use trying to teach maths and we need to talk about rugby instead.

You have to be a bit of a showman in teaching and I love all that. My father, a solicitor, worked until he was 85. He simply lived for his job and I am the same. I will carry on until I drop or until the school doesn’t want me any more.”

Lord Wandsworth is showing no signs of wanting to sign off Mr Goldsmith. On the contrary, Ian Power, the school’s headteacher, prizes him as one of his most inspiring teachers. Maths is the most popular A-level subject and is taken by over half of the sixth form. Of 18 candidates who completed A2s last year, 15 got A grades. “David is charismatic and idiosyncratic, a fantastic mathematician,” says Mr Power. “He demands the best from students and has clear expectations, but he is also an avuncular figure, a funny, pleasant man. He is an Ipswich Town supporter and we rib him about that.

“When I came here, David was 70 and I thought, ‘wow! Still teaching and enjoying it’. He is from another era but he is flexible enough to understand that young people’s expectations have changed; that they’re not prepared to sit through boring lessons any more, that they want to be entertained.”

Indeed, Mr Goldsmith still has a relatively young family, having married late in life when he was nearly 50 and fathered three sons. But he is adamant that he did not need to stay in teaching to support his family; he stayed because he wanted to. Mr Power believes students appreciate that level of commitment. He says: “David has a 40-minute drive to get to school. It’s not a question of just popping in. Pupils know he comes because he wants to help them, and they are flattered by that.”

Henderson Clarke and David Goldsmith are still teaching because they want to. Both their heads believe teachers should be able to carry on if they are still good and they choose to. Equally, they believe teachers who want to get out before 65 should have the choice. Mr Patrick says: “I do everything I can to recruit and retain good teachers, but raising the retirement age to 65 is one of the worst things the Government could have done.”