Crisis mismanagement: Maria Miller was right to resign. But avoidable errors mean her departure has damaged both parliament and the Tories

In the end, Maria Miller did not even last the full 10 days beyond which – says a Westminster maxim erroneously ascribed to Alastair Campbell – a headline-whipped minister cannot hope to survive. Less than a week after the Culture Secretary’s ill-advisedly curt apology for her failure to cooperate with enquiries into controversial expenses claims, she duly stepped down.

Quite right, too. She may have been cleared of the charge of using public money to subsidise her parents’ living costs, but that was no longer the point at issue. The combination of her mulish response to efforts to get to the bottom of the matter, and her manifestly unapologetic apology – all 30 seconds of it – rendered it impossible for Ms Miller to remain in the Cabinet.

A resignation just hours before the weekly joust of Prime Minister’s Questions was always going to prompt speculation that, despite the support in public, Downing Street gave a shove in private. David Cameron did not rise to the bait, but Ms Miller’s equivocal statements did little to scotch the rumours. Either way, the desired result was achieved. While the subject could not be dodged entirely, the Prime Minister avoided having to defend a colleague whose position had become so obviously indefensible.

The damage is done, even so. Rightly or wrongly, Ms Miller’s financial arrangements have reignited suspicions about MPs’ motivations and dealt a blow to hopes of the political class restoring its collective reputation after the catastrophe of the expenses scandal. Meanwhile the spectacle of parliamentarians overturning the recommendations of the independent standards commissioner – thus slashing Ms Miller’s repayments from £45,000 to £5,800 – has reinforced the sense of Westminster as a club that plays by its own, self-determined rules.

There are repercussions for Mr Cameron, too. For all the appeal of his claim that firing someone at the first sign of trouble is weakness, not leadership, more than a whiff of poor judgment remains. Given the ferocity of public opinion on MPs’ expenses, the gravity of Ms Miller’s situation should have been immediately evident. It is one thing to stick by one’s colleagues, but quite another to grossly mistake the national mood – particularly for a Prime Minister routinely accused of being “out of touch”.

To clean up the mess, the rules must be changed so that MPs no longer police themselves. But the matter does not end there. It might seem obvious that the principle of independent oversight should apply to the media just as it should to Parliament. Yet there can be little doubt that some newspapers have put the boot in extra hard over the past week because of the Culture Secretary’s role in crafting such rules, in the aftermath of the Leveson Inquiry. An immature attempt by one of Ms Miller’s advisers to bully journalists on that basis only played into fears of political manipulation.

Except that the proposed royal charter-based system would take press regulation far from the secretary of state or, indeed, any politician. Both MPs’ intercession over Ms Miller’s expenses and the rough treatment meted out by axe-grinding newspapers make the case for a swift resolution more strongly than ever. Of the tasks facing the new Culture Secretary, Sajid Javid, this is both the trickiest and the highest priority.