The 1944 play of this title has not been seen before, though its "finished" version, Love In Idleness, was performed by Alfred Lunt and Lynne Fontanne in London and New York.
The earlier version was written at the express request of Gertrude Lawrence, who then pretended she had never even asked Rattigan for a play.
The Lunts' version seems to have crept back into the "unsullied" first script at Jermyn Street, as the roles of the cabinet minister and his lover are not too unequal.
It's good to see the play, but it's a lumpy old thing, with several Rattiganesque ingredients that stick in one's craw: the insufferable "Hamlet" boy with his feeble socialist ideals which are of course set up to be ridiculed.
And there's the usual sentimentality about the bedsit life as opposed to the airs and graces of Kensington and Westminster. And there are no good jokes, and no real fizz in the writing.
Unlike After the Dance at the National last year, Less Than Kind is very small beer indeed. But it's heartening to see that Michael Simkins hasn't deserted the stage for the newspaper opinion columns entirely; and especially good to see Sara Crowe once more.
Sara was for a long time saddled with her television fame as the Philadelphia cheese girl, and her performances invariably exploited her comic voice and bubble-headed silliness in the adverts.
As Olivia Brown in Less Than Kind, she reveals a strong, still centre to her acting, and she is very nearly talking normally again. But I do hope the endearing squeakiness hasn't disappeared altogether.
Even though we'll never admit it, we need to hang on to our prejudices about people, and I've certainly got a few about Rattigan's post 1956 plays.
And unlike former Times critic Benedict Nightingale, who unpacked a groaning conscience and twisted himself into a lather of repentance in a recent article, I'm in no mood, particularly, to say I was wrong about lesser Rattigan plays such as Ross, or Bequest to the Nation, or even In Praise of Love.
The latter is always held up as one of Rattigan's finest. We'll have a chance to see when it's revived at Chichester. I was inordinately rude about the play when it first appeared in the West End starring Donald Sinden and Joan Greenwood.
Rattigan and I had a protracted, and amicable correspondence, he writing from his chambers in Albany, me from my bedsit in Kilburn; it was like 84 Charing Cross Road.
Eventually, he sent me an inscribed copy of the play when it was first published by Hamish Hamilton, signing it with best wishes -- and "without -- well -- prejudice; I was going to say," he continued on the fly-leaf, which is open before me as I write, "without whom I wouldn't have a real stinker to read out at parties. Until yours, I had to rely on Agate's on French Without Tears, and my friends had got to know it by heart..."
Ah, those were the days: battle lines drawn up. In Praise of Love was in fact a double bill of After Lydia, in which the heroine tries to conceal from her husband that she is dying of leukaemia; and Before Dawn, a really scrappy re-working of Sardou's melodrama, Tosca, better known as Puccini's opera.
They were, I had chippily opined, "the product of a spirit languishing in the glow of a former heyday." But a few years later, and before he died, the King's Head revived The Browning Version, and the critics, including me, were unanimously enthusiastic.
Rattigan just about sensed the tide may have started to turn once more in his favour, but it's probably true that he never felt as thoroughly rehabilitated as Coward did by the time that he died in 1973.
He was ill and frail, but he turned up to the pub theatre in Islington on the First Night and sat elegantly throughout the performance, dressed in a blue suit, sipping brandy and water, and graciously accepting the compliments of the audience at the end.
Had he written any enduring plays? Certainly: I love French Without Tears and Flare Path, and I'm as keen on The Browning Version, The Deep Blue Sea and Separate Tables as anyone.
But then, these were his best plays, and always critically approved. No breast-beating needed.