Just before the end of term I had the shocking news that I’d been promoted.

Last term I was a hard-working English teacher, but next term I’ll be joint head of department. This is scary stuff and the pressure is seriously affecting my summer holiday.

I’d planned to go the south of France for three weeks, but as soon as the promotion news struck I thought I’d better be back for the GCSE results so I cut the holiday short by four days. Previously, I might not have phoned school mid-holiday to get the A-level results but this time I did. I certainly wouldn’t have taken a book called Effective School Leaders on holiday last year but, yes, this year I was that sad.

But what does promotion really entail? How much familiar old skin have I got to shed to ensure that I start the new term resembling someone who can carry off the new job description?

First of all, I need to be much more professional. No longer can I be the drunken bint at dinner parties; the one who unsuccessfully chats up the single 25-year-old in slurred iambic pentameter. Instead, I’m going to have to defend and discuss all aspects of education with every concerned parent present. As the port is passed I’ll need opinions on different exam boards, private versus state education, inclusion versus integration. I suppose I’ll need to log on to Cathy Kelly online - oh no, she’s the romantic fiction writer, I mean Ruth Kelly, the one who opposes A-level changes that 90 per cent of teachers think are a good idea.

Will promotion really mean shedding that part of my former self that enjoys staff-room discussions on last night’s gripping Channel 5 porn and conducts a survey asking teachers whether they have ever taught without wearing knickers. (A shockingly high number, I discover.) I’ve also quickly found out that getting promotion is incredibly expensive.

A few extra grand in the annual pay packet has suddenly led to a few extra grand being spent. Within days of the promotion, I’d put in an offer on a new house with an X-rated mortgage and started cruising car showrooms.

For three years I’d been happily driving a Ford Ka but suddenly I felt the need to buy a new Renault Megane - was this a metaphorical shakin’ ass moment as well as a physical one? There is also the emotional trial of internally advertised promotions, physically represented by me tiptoeing (while smiling confidently) around the department avoiding the daggered stares and gasps of incredulous disbelief from colleagues. “She didn’t?”; “She did!” Maybe there’s already a voodoo doll of me in the stationery cupboard suffering from the slings and arrows of a thousand staples, drawing pins and compass points. No wonder I developed a nervous tick at the end of term.

But these worries are surely nothing compared with the real meat of what promotion involves: I’ve got to cut the waffle and turn in the results. For my interview I had to deliver a presentation on “Taking the Faculty Forwards” and it was relatively easy to prepare a glossy document full of ideas and statistics. The tricky part, the oh-my-god-this-is-for-real aspect has only just hit me. I’ve now got to put reality where my wine-infused ramblings were printed and achieve more than 84 per cent A-Cs; solve the issue of under-performing boys; and maximise the A*s in mixed-ability state-school teaching.

I need to recognise the strengths of all members of staff; implement more after-school revision, mentoring and enrichment sessions; have weekly meetings with parents; be responsible for budgeting. And, above all, I need to metamorphose into a creature that looks like a regular teacher but conceals, under a Per Una sale suit, the skin of a rhino and the heart of an angel.

And what about discipline issues? I’ve never been one for showdowns with pupils and have been referred to as a bleeding-heart liberal. Will this need to change? Yes? Can I buy a stun-gun on the Internet? And is there an NUT discount?

What will my management style be like? Is it something I can decide or does my DNA already dictate it? Will I be an old-style Captain Kirk, staying on the bridge making decisions, or will I be the up-to-date kind who calls meetings? Will I be like a previous department head who stayed behind on Friday night leaving memos on everyone’s desks or will I be far too chilled and advise a month’s paid leave because little Jimmy said the F-word?

School starts again on August 30, which is both my birthday and my first day in this new job. And I feel like I’ll be climbing Everest in stilettos.

But at least I wrote a glossy document about it; at least it’s been conquered by a thousand teachers in a thousand schools before; and at least I have supportive staff around me to hold my hand... when they’re not disappearing into the stationery cupboard with that voodoo doll.

Ted Wragg returns next week