Its status as an unimpeachable classic - one that is even appreciated by bona fide, elbow patch-sporting intellectuals - looms large over the rest of the genre.
Presumably, as the man in charge of policing local councillors' behaviour, he is a man of unimpeachable moral standards himself?
That pitch might have been better made against a track record of unimpeachable integrity, where promises had been kept, failure openly acknowledged, and honesty had been the keynote of his government.
He is almost unimpeachable because to criticise him is seen as poor form.
In unimpeachable academic language, those who wish to squander their talents have been presented with yet another excuse to add to the great armoury of excuses that have already gained currency.
They are unquestionable, unassailable, unimpeachable .
But one unimpeachable witness in the court of history is sufficient.
His track record is unimpeachable and there can be no doubt that he knows the game inside out.
It was bad enough that at the best possible time to kill this monstrous legislation, in the Commons, with unimpeachable democratic legitimacy, we failed because we couldn't be bothered to turn up.
The guys who made these selections are above reproach, they're unimpeachable , these fellows.