It is part of a campaign to save her school from closure, an event that would leave her with an uncertain future.

“A lot of the staff are nervous. If our school merges with two other local schools, as planned, that could mean four or five maths teachers looking for a job,” she says.

Like many in her situation, she is reluctant to move away to find alternative work.

“I came here from a small village so Hornby is perfect. I live with my boyfriend and step-daughter, and my wages pay the mortgage.”

Kim is one of a growing number of teachers whose schools are under threat as a result of falling rolls: the effect of a century-long decline in birth rates, which accelerated in the 1990s, and a drift towards the prosperous south-east.

According to the most recently-available figures, there were half a million surplus primary school places in England in 2006, 12 per cent of total capacity. This will increase by a further half a million by 2010, according to local authority predictions. Wales has a primary surplus of more than 16 per cent. There are no figures on surplus places available for Scotland, but primary numbers have fallen by over 30,000 since 2002. As the children of the population dip become teenagers, its effect is increasingly being felt in secondary schools. What impact will this have on teachers’ jobs?

The picture is not uniform across the UK. In 2006, 12 areas in England had surplus primary places totalling more than 17 per cent of their stock. Rutland, Portsmouth and Knowsley on Merseyside were the worst-affected; more than 40 per cent of primary schools in Knowsley had more than a quarter of their places spare. London and its environs, with a growing population, generally have a primary surplus of less than 10 per cent.

In this climate, it is not hard to see why local authorities have rationalised by closing and merging hundreds of schools, more than 1,600 in England from 2002, a rate of over 250 a year. That’s around 6 per cent of the 25,000-school total.

Liverpool, Nottingham, Bradford, Birmingham, Essex and Hertfordshire have topped the league by closing over 40 each. Scotland and Wales have both closed 80 out of approximately 2,800 and 2,000 schools respectively (that’s around 3 and 4 per cent of their totals).

Although falling rolls aren’t always the reason for school closures, they play a large part. Martin Burgess is head of Skerton Community High School in Lancaster, threatened with closure after pupil numbers fell from around 500 to under 250 in a decade. He says: “The school needs around 700 pupils to be economically viable.”

With funding dependent on pupil numbers, falling rolls affect the school’s ability to deliver. The Department for Children, Schools and Families gives local authorities around pound;5,400 per pupil. Councils then decide how much to allocate according to their own formulae.

“If 60 kids leave Year 11, but only 30 come in at the bottom, I would lose pound;200,000 out of our revenue - that’s the cost of employing eight staff,” Martin says. He says this means he cannot fund enough teachers to set children by ability, or provide them with the breadth of subjects they deserve.

Where possible, schools and local authorities prefer a process of natural attrition: letting older teachers retire without filling vacancies. There are no national figures on the scale of job losses caused by falling rolls, but The TES Magazine surveyed a sample of local authorities within the traditional north and east Yorkshire boundary, a part of the country severely affected, and found that job losses had taken place in most areas in the year 2006-07.

In Middlesbrough (primary surplus places at 14 per cent), school closures were discussed but no jobs were lost. In Redcar and Cleveland (11 per cent), there were five redundancies as a result of falling rolls, one compulsory. In York (11 per cent) there was a merger and 15 voluntary redundancies.

North Yorkshire (16 per cent) lost 10 teachers, amid one amalgamation and one closure, mainly because of falling rolls. Against a background of multiple amalgamations, East Riding (16 per cent) lost 13.9 full-time equivalent teaching posts, although this was mainly due to budget pressures. The only other unitary authority, Kingston-upon-Hull, could not supply figures. In sum, at least 30 teachers have been lost as a result of falling rolls in north and east Yorkshire in the last year.

John Howson, a recruitment analyst and visiting professor of education at Oxford Brookes University, warns education is going to become even more of a buyer’s market in the coming years and advises teachers to know the situation in their local area: “Don’t bury your head in the sand. If necessary, make sure your professional association is on the ball and can negotiate for you,” he says. As always, teachers in London and those specialising in shortage subjects will find themselves in an easier position. Likewise, high-performing schools and those that have involved a significant outlay, such as Building Schools for the Future, are less likely to be closed down because councils will be reluctant to waste new refurbishments. The increasingly market-driven nature of education can exacerbate the misery caused by falling rolls in some places, as pupils abandon less popular schools, resulting in a spiral of decline.

Of course, many in the profession believe falling rolls are an opportunity to exploit smaller class sizes and explore imaginative ways of working. “Sadly, the default position is often to reduce the number of schools,” says John Bangs, head of education at the National Union of Teachers. “But federating them would allow staff to work across a number of schools, sharing their specialist expertise.”

When schools are merged or closed - the legal term is discontinued - staff will generally be invited to apply for a post at the new school, and be given a similar post with an equivalent salary, safeguarded for a set period of time, if they are unsuccessful.

Local authorities are usually keen to avoid redundancy because of the cost, and heads because of the effect on morale, and departures will be voluntary if possible.

The future for school rolls is uncertain: birth rates are picking up again and are predicted to rise by a total of 31,000 a year by 2010 from a base of 766,000 in 2006-07, according to the Office for National Statistics. Immigration is projected to swell the population by another 2.1 million by 2016, but it is not known how many of these new arrivals, if they come, will settle and have children. The effect on school closures, and teachers’ jobs, is difficult to predict.

For the time being, teachers such as Beryl Jones, 55-year-old head of Ysgol Rhydyclafdy primary in the village of Rhydyclafdy, in Gwynedd, North Wales, which is being closed after its pupil numbers fell to only four, will have to face the music.

“The closure has become a self-fulfilling prophecy: as soon as it was mentioned, parents started taking their children out,” she says. “It’s very sad. The school is the centre of the village. You’ve got personal feelings, but at the end of the day you have to try and be realistic ”

What teachers can do

- Know the situation in your area: are pupil numbers falling, and how hard hit is your school?

- If there is talk of your school being closed, keep your union representative well informed.

- If the closure is going ahead, find out what provisions are being made. Will you be invited to reapply for your job? Your head and union representatives should keep you up to date.