The idea of a clause in law that makes certain royal charters tamper-resistant (without specifically mentioning the press regulator charter – the wording refers to charters after a March date in “an industry”) was part of the talks between the three main parties when the PM walked away from them on Thursday.

He has come back to the same dish he turned down. In the “who blinked first?” assessment, I’d say that makes him the blinker.

Mr Cameron’s team point to the full-blown statutory approach to press regulation threatened or already voted on in Lords amendments. But as No.10 knew, those were outliers, menaces to achieve what had become the central shared Lib-Lab project (as shared in the charter plan published by the Lib Dems and Labour at the weekend).

True, Labour and the Lib Dems had moved from their original “full fat Leveson” approach and over the months come on board with a royal charter idea originated in Oliver Letwin’s capacious brain. But in terms of the journey in the last 72 hours, it looks like David Cameron travelled the greatest distance.

One Tory PPS said David Cameron had “marched us up the hill again, only to march us down… Every time he does it it it hurts his authority.”

David Cameron’s team is saying it won concessions on whether there should be any journalists on the code committee, it ripped up a clause that would’ve allowed the oversight committee to fail the regulator, even if it had met its criteria. It claims Labour and the Lib Dems have moved on who writes the code, though I’ve yet to see the detail on that.

But David Cameron painted his opponents’ plans as unworkable on Thursday and is today signing up to a slightly adjusted version of just that. He “wanted to call their bluff”, one Cameron aide said. History may judge it was Mr Cameron whose bluff was called.

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