For this Iron Lady extra, the Oscars are just a formality

A bit part in The Iron Lady gave our columnist a thrilling chance to see a truly great actress at work, close up.

Like most men in their 50s, I've reached the age when middle age has me firmly by the throat. I have to sit down to put my socks on, and where once I turned the light off for romance, nowadays I turn it off merely for economy. Worse still, if I stay up all night I'm thoroughly unfit for purpose the next day.

But on Sunday, February 26, I'll be making an exception when I settle down at midnight to watch the 2012 Oscar ceremony live on television. With the aid of some energy drinks I'm hoping to make it through to the Best Actress award, due to be presented at about 5 am in the UK.

For once my interest in the ceremony is entirely personal - to see if Meryl Streep's mesmerising performance as former Prime Minister Margaret Thatcher in The Iron Lady gains her the prized statuette. For while I doubt she'll be thanking me personally in her acceptance speech, the delicious fact remains that I have one line of dialogue in the movie, and (as long as you don't miss the opening five minutes) a fleeting appearance opposite Hollywood's first lady.

The job specifications for my two days spent on the project, which was shot at Pinewood studios near London last spring, was easy: one scene as a guest at a dinner party, thrown for the ageing ex-premier by her daughter, during which Mrs Thatcher, now struggling with the onset of dementia, tries to comprehend the conversation flitting back and forth across the cutlery.

Crucially I had the final line in the scene. "Nice to have met you Mrs Thatcher" may be only six short words, but they'd guarantee that I would share the lens, however briefly, with Hollywood's first lady.

For me, the preparation was easy: five minutes to get into a lounge suit, a quick powder in the make-up chair, and plenty of time to tuck into the free location breakfast before filming commenced at 8 am.

Streep's ordeal, by contrast, was far more arduous, involving up to three hours under the expert guidance of make-up maestro Mark Coulier, including the fitting of specially designed dentures, a false nose, artificial cheeks and an extensive wraparound rubber neck, each section delicately manoeuvred into place before being blended into the whole with infinite care.

In addition her nose was widened with a small segment of arced silicone, while even her hands received specialist attention, the skin tone accentuated by painted liver spots and discreetly placed rubber bands around the wrists to exaggerate the veins.

The final touch was being fitted into a specially designed fat suit to replicate the 86-year-old's now-comfortable contours.

Nonetheless. I was ill prepared for the astonishing likeness that greeted me when Streep herself finally stepped onto the set just before 8. So extraordinary was the effect that even at the distance of less than two feet it was impossible for any of us gathered round the table to see where Streep ended and Mrs Thatcher began. The only indication that the woman beside me was not the actual politician but an astonishing facsimile were the huge industrial fans that pumped out freezing cold air whenever the cameras stopped rolling. This, I learnt, was to ensure Streep didn't start sweating - perspiration, it turned out, is the greatest enemy of the prosthetic as it bubbles up through and has to be pricked with a pin to allow it to evaporate.

Having sat down, Streep introduced herself to the other actors individually. "Forgive me if I don't drop this accent", she said in the unmistakable (and uncanny) tones of Mrs Thatcher. "But if I drop the accent between takes I may never get it back again." Such disarming courtesy ensured I was hers for life.

The next two days provided me with an opportunity to witness, up close, an actress at the very height of her creative powers. Some people have described her portrayal as a supreme impersonation, but such faint praise denigrates the art of acting: for Streep has managed to inhabit the character in the way only truly gifted actors can manage. Critics - including the current prime minister, David Cameron, while praising her skill, have criticised the movie for portraying the ex-premier in bewildered old age while the incumbent is still alive. That is a debate for others, not me. For now, I am content to be able to boast to my grandchildren that I shared a camera lens with one of he most superlative performances of recent Hollywood history.

"Nice to have met you Mrs Thatcher." It may not be the most profound line ever spoken on celluloid, but I've rarely been prouder. Call me an old luvvie (and many do), but if Streep prevails come the early hours of Monday morning, mine will be the loudest cheer this side of the Atlantic.

And if I make it through to 5 am, I might just give make-up maestro Mark Coulier a call myself. If anyone can make me look half-human again after ten hours in front of a TV set, he, surely, is the man to do it.

Michael Simkins is an actor and writer based in London