'I found York a rather stifling place and I just loved the theatre. All the people I met were really vibrant and exciting; I liked the way they talked and what they talked about. I saw She Stoops to Conquer and I just thought: 'Oh, I'll have to have a go; if I don't have a go at this I'll regret it for the rest of my life.' So I asked the actors which were the drama schools to apply for, none of which I'd heard of, apart from Rada, and so I applied, did my auditions, and mum and dad were brilliant, got in and went: it was as simple as that.' No path up to the peaks of the British theatre has ever been smoother. She conquers another summit this week when she appears at the top of a West End bill for the first time, opposite Mark Rylance in Much Ado about Nothing. She says she's never seen another Beatrice, and she has cut her second line.
When another Amazonian six-footer comes along with lithe gait and shoulder-
length mane they'll doubtless tag her the new McTeer. But there's more to the likeness with Redgrave than appearance. She has the same serenity of expression, but also the facility for portraying raw nerves. No one does blind panic quite like McTeer - her eyes lurch out as if on springs, her nostrils flare ever wider. Her Katerina in Ostrovsky's The Storm for the RSC was a masterclass in febrile paranoia. 'If you can do that kind of stuff and get away with it, you get a lot of kudos.' She says this with a joshing modesty that is half serious and wholly typical.
'Her principal attributes are intelligence and her physical ease on the stage,' says Bill Alexander, who cast her as Titania and Hippolyta in A Midsummer Night's Dream at the RSC in 1986. 'She's one of the most brilliant people physically that I've worked with. Whatever it is that Vanessa (Redgrave) has, she's more like it than any of the others. It's a singularity - a non-acting presence that is none the less very powerful. She brings freshness to any part she plays.'
'I know a lot of people don't like being told it but she is extremely beautiful and she has a fantastic physical grace on stage,' says Simon Russell Beale, the RSC star who acted with her in The Storm. 'She's far too clever to be purely instinctive. She works it out. Her Katya in last year's Uncle Vanya at the National was the only one I've ever seen where you actually believed she was a concert pianist. I don't know how she did that. She's very elegant, but it's more than that. She has a sort of aristocratic control. She is beginning to become a great actress.'
There were four years between the one doomy Russian play and the next, during which McTeer avoided the stage altogether. On holiday in Africa, everyone else ate some prawns and went down with a basic dose of food poisoning, but she was unscarred until she returned home to chronic migraines and temporary blindness in one eye. 'It was just a nightmare; I felt so sick and I kept fainting. Every morning I'd wake up so tired with such a headache feeling so ill. In fact I dropped out of the RSC: they were really nice about it. After that I took six months off and I didn't really get strong again for a couple of years.'
When she eventually returned to theatre, Chekhov turned out to be more restorative than he usually is. 'For four years I'd got so used to just acting in front of people I knew - a film crew. The idea of acting with a whole load of people I didn't know watching me I found incredibly intrusive. I thought: 'What are they doing here?' At first I had to completely shut them out, and that's not the point: if you shut them out why are you doing the theatre? It took a good week or so of previews to think: 'No, this is nice.' '
The illness, as well as her early success, perhaps explains why people think she is older than her 31 years. In the flesh her face is much rosier than it ever looked as Vita Sackville-West in Portrait of a Marriage, the BBC drama that made her name. 'I did get to a point when I just got sick of looking in the mirror and constantly seeing this incredibly knackered person. I just thought if a script arrives and it has 'She cries' in it - out. For about a year I refused to do anything that had a sob in it.'
It also helps to explain why she still isn't much recognised in the street, though since A Masculine Ending and Don't Leave Me This Way, in which she and Imelda Staunton play Joan Smith's jaunty pair of eccentric amateur sleuths, that is changing. It is a strange irony that if she continues to put out such high- quality work, and to have no need for demeaning odd jobs, then her relative anonymity might continue. Mass audiences simply haven't cottoned on to her yet, just as Juliet Stevenson was a theatregoers' secret until Truly Madly Deeply.
We met in her modest flat in north- west London. On the wall there's a gloomy portrait of Janet as Vita and a mock-up from Shepperton of a painting that still hangs in Vita's study. There's also a very convincing mock-stripped ceiling which McTeer did herself. I fancy she enjoyed working very hard to create something that looks simple and pared down. At work, she does it every day.
'Much Ado about Nothing': Queen's, London W1 (071-734 1166), previewing now, opens Tues.