Carey Mulligan and Bill Nighy on stage together – being able to watch two big names in Portsmouth, I mean, what’s not to like?

National Theatre Live at the Vue Cinema on 31st July gave us that. In fact, it’s better than being in the West End’s Wyndham Theatre from where it was broadcast. You can eat popcorn and icecream if you like in seats designed for a 21st Century frame. Though this was the “Encore” broadcast, a re-run of a play originally broadcast live on the 17th July, and starring two hugely accomplished actors, the experience really gives you the feel of the live event.

It does take some adjustment, seeing stage acting on screen. When Kyra (Carey Mulligan) enters with her shopping, her body language as she heavily plonks her bags on the table feels distastefully overdone. Her peculiar treatment of the text books she brings home from her work as a teacher jars the eye used to the nuanced performance of the big screen.

Just so with the arrival of 18-year-old Edward, walking into the flat on the sink housing estate where Mulligan lives because she left the door open. But then, this is hard to swallow for another reason. I mean, who leaves their door open on a snowy winter’s night in a clearly troubled housing estate? I mean really, who does that? It seemed strangely middle-classly cutesy, as if Hare had forgotten Kyra lived in the inner city, but in a little country cottage somewhere in the Home Counties.

Their initial interactions were what I had feared the whole play might be. At times unreal but with occasional moments of brilliance in the dialogue, something did not gel. Edward was clearly a 2D device used to set up what was to come later between Kyra and Tom (Bill Nighy). It was uncomfortably done. Edward’s flouncing out at the end of the scene with his “You’ve got to speak to him Kyra!” was straight out of Victorian melodrama.

Tom’s arrival was much better. The story unfolded. Businessman Tom and teacher Kyra had once been an item – having an affair while he ran his expanding chain of restaurants through the 1980s. Their affair had been discovered by Nighy’s wife and Mulligan (a nice middle class woman) had gone into teaching in East Ham.

Along the way, there were moments of comedy that highlighted the snobbery of the business classes and the idealism of liberal middle classes. Essentially the play was about the collision of two world views – the money-minded and the liberal left, interspersed with some cooking and a break in the middle for a shag, which thankfully happened in the interval.

As a writer, it was interesting to see how basic the play was. David Hare, one of Britain’s greatest living playwrights, used cookery to give the two actors something to do while they slugged it out with each other or came to understandings of each other’s views, or grew close, or grew apart. The cooking (I’m sure a symbol of consumerism, community and shared endeavour) alleviated the boredom of the pair standing and pontificating about how their particular views of the world were right.

Hare made a pretty good fist of making Nighy’s character likeable and sympathetic, but it was clear as the play went on that this wasn’t going to be one of those: “make your own mind up” types of plays. Carey Mulligan’s Kyra, the impassioned and idealistic middle class liberal who had given up everything to be a teacher was clearly the character with whom Hare most identified.

Towards the end , both characters ceased to be people at all. Mulligan’s Kyra especially became a mouthpiece for Hare’s opinion, with a long, tedious rant about how marvellous the public sector is and the platitude that “Wealth Creation” was not the truly important thing about life.

This was clearly intended as the highlight of the second half: a kind of super-eloquent Sixth Form Common Room rant, in which the Kyra rehearsed Hare’s particular political bugbears, and received spontaneous applause from the Wyndham’s sympathetic audience. He had pressed the right buttons for his audience, then.

By this time I genuinely had the feeling that Hare had written the play by tickbox. “Oh, okay, so I’ve now done the bit where he accuses her of being guilty. Now let’s do the bit where he accuses her of running away because she’s still in love with him. Okay, now we do the bit where she accuses him of cowardice. Okay, now selfishness…” and so on.

By the time you’d got to the end, just about every base was covered. The two characters were indeed symbols (something Hare himself highlighted in his script) who covered all the angles in the eternal battle between the private sector and public services, and between the unfaithful businessman and his young lover, picking up hypocrisies along the way.

But one really important angle was never approached.

Kyra mocked the idea of people involved in “Wealth Creation”, pointing instead to “real people” as if people involved in business are somehow “not real”. And that was the heart of the problem.

There was a much more profound discussion to be had here about that unhappy marriage, in which business and social enterprises are spliced together. Each is dependent on the other. Business is reliant on education to produce people with innovation and drive, self-belief and originality. As such, business cannot complain about taxation. It is reliant on the use of those resources to supply its employees and its consumers. The employees of business are also “real” people, prone to all the weaknesses of greed and stupidity and selfishness if that connection between business and the wider community is not nurtured.

At the same time, workers in State education (symbolising the public services) have trouble accepting the fact that without business they would not exist because no taxes would be taken to pay their wages. The fact that today there are fewer public sector wage packets than there were 6 years ago is a much bigger discussion about how the marriage works. What the covenant is between the public sector, the wider public and business was not even considered in this play.

That, I suspect, is partially because Hare is not interested in this more nuanced way of looking at the world. His writing comes straight out of the idealism of the 1960s. It’s also because Skylight was first performed in 1995, way before the Credit Crunch was a twinkle in Tony Blair’s eye. And to be frank, it showed.