HOW does a softly-spoken, articulate actor who suffers from claustrophobia become one of the most terrifying characters in theatre nine times a week?

With the help of a lot of prosthetics, two wigs, a tonne of make-up – and a spare half-hour.

Earl Carpenter, the Southampton-born West End star, has returned to one of his most famous roles – in Phantom of the Opera.

I joined him backstage at Milton Keynes Theatre where he’s about to don the make-up and mask for a matinee performance.

The 42-year-old has joined the 25th anniversary UK tour, replacing John Owen-Jones, and is due to perform at a four-week home town run, which gets underway at The Mayflower in January.

“I’m terribly claustrophobic,” he muses as a latex cap is placed over his head by his make-up artist, squeezed into a small dressing room which nevertheless has a star on the door and showbiz lights around the mirror.

“I was getting in a terrible state about all this, but then I thought you’ve got to do this, this is what you have to wear for your job.

“John sat in all this for hours between the matinee and the evening performance, but the thought of doing that filled me with the fear of God.

“I get involved in doing the make-up though. I like painting and it speeds the process up.

He wasn’t quite as relaxed about a visit to the man behind the Dr Who prosthetics who fitted his ‘mask’ by ‘freezing’ his face.

Each mask costs several hundred pounds and can’t be reused, so it’s an expensive business donning them eight or nine times a week.

“I couldn’t breathe! The lengths we have to go to to entertain people!,” he jokes.

And entertain Earl does.

He puts in such a spectacular performance that afternoon that a notoriously subdued matinee audience are on their feet giving him ovation after ovation.

It’s his second stint as the Phantom, after a West End run in the show.

But, he tells me as microphones are being fitted to his eyebrows, it might as well be a brand new role.

“It’s completely different, the fact I’ve played the Phantom before is a hindrance if anything.

It’s a real challenge.

“It’s taken me a while to find my routine to be honest. The costume design is similar, but everything else is very different, including the make-up.

“The whole production is on another scale, a very different piece. The London production was more black box, this is a lot more real, the character and everything.

“We’ve reduced the orchestra, you can’t tour an orchestra of 27, so I’ve spent quite a lot of time sitting in the pit listening to the arrangements. It’s amazing.”

It’s been quite a year for Andrew Lloyd Webber’s legendary show, which celebrates quarter of a century with a new reimagining by Cameron Mackintosh. Earl performed the title song from Phantom of the Opera at the Royal Variety Performance alongside Pussycat Doll Nicole Scherzinger. He had no idea who she was, but was honoured to be a part of musical theatre history.

His concert show Three Phantoms also enjoyed another sell-out night in Southampton.

Earl is somewhat of a Mayflower regular, having also appeared in the 25th anniversary production of Les Miserables as Javert.

He’ll be commuting from his home on the Isle of Wight throughout the run at the Mayflower, but will be more nervous than ever.

“It means you know people and you have to be good! No, Southampton’s always a great one to play. It is special to me and I’ve been in some pretty big shows there over the years.

Plus, it’s the only time my mum gets to see me!”

Earl’s mum will be glad to note, Phantom of the Opera runs from Wednesday, January 23 to Saturday, February 16.