Wiktionary
n. (context chiefly British English) educated people with liberal opinions and attitudes
Wikipedia
The chattering classes is a generally derogatory term first coined by Auberon Waugh often used by pundits and political commentators to refer to a politically active, socially concerned and 'highly' educated section of the "metropolitan middle class", especially those with political, media, and academic connections.
Usage examples of "chattering classes".
And so Mark Armstrong entered the day: a white, overprivileged, overweight, late-middle-aged Englishman - with, according to Fred, no symbolic significance on a world stage which now belonged to women, blacks, Muslims and former members of the Soviet Empire - sometimes gently satirised as one of the chattering classes, trying to concentrate on Rudolf and the franchise bids, his future, the desperation in Northern Ireland, the situation in the Gulf, a tone he had not quite resolved in Nick's call.
He might not be a representative of an ancient type, as Paul had first thought, but he was clearly of almost a different species than the chattering classes among whom Paul had spent most of his life: the man used words the way a traveler in the desert rationed his last canteen of water.
There was an immediate outcry from the chattering classes, whose strongly held views were reported on the front page of the Guardian.
The chattering classes weren't so copacetic about Reagan's religious beliefs when he was in office.
The prevailing view now emerging was not that of the chattering classes of the long-dead TwenCen.