Earlier today, it seemed to me that the citizenship circus might be dying down. There were bits and pieces around, but really the day was oddly quiet. I was beginning to wonder if perhaps Malcolm Turnbull had judged things correctly in deciding not to order an audit of any kind, and in sticking to his declaration that it was up to individual MPs to sort themselves out.

And, after all, there was one razor-sharp reason for staying his hand: the surfacing of just one more lower house MP with their citizenship status in doubt might bring down Turnbull’s government.

By “earlier today”, I mean about a minute before the prime minister called a press conference, with a dramatically short ten minutes’ notice, at which he announced he would be asking for a disclosure regime to be put in place.

There are a few things to be said, but the central fact is this: Turnbull has very possibly just set in train the events that will bring about the downfall of his own government and the end of his prime ministership.

Given the farce that we have seen unfold so far, encompassing not only the deputy prime minister and the various senators who have gone, but the multiple questions that remain over other MPs, it seems extremely unlikely that every government MP will get out of this with their job.

This does not have to mean the instant end of the government. But it could easily mean the end of majority government, should just one byelection be lost. It might mean more. Either scenario would create an order of chaos that might surprise even Turnbull, who has been, over recent months, no stranger to chaos. This is not a melodramatic conclusion. Late last week senior government sources told Samantha Maiden at Sky News that “everyone knows why we can’t have an audit”, namely that an audit was likely to see the government fall, bringing a snap election. Turnbull might win that election, but the odds would be against him right now.

What Turnbull announced today was, he insisted, not an audit. He said this because he wants the credit for doing something without being able to be accused of backflipping on his bellowing attacks on the idea of an audit. (Bill Shorten, too, did not call for an actual audit.) Still, he’s right. It’s a disclosure regime, similar to the one in place now for MPs to declare commercial interests and gifts. MPs will have to declare they were not a citizen of another country when they nominated for parliament; they will also have to list various facts, such as the dates and birthplaces of their parents, previous citizenships, and citizenship renunciations. It will be put in place soon, and apply to future parliaments as well.

This is fairly useless. First, the declaration system right now does not work. MPs regularly flaunt it, and rarely suffer for it. Tony Abbott was once two years late. Joe Hockey once waited 14 years.

Second, the PM insists the federal director of the Liberal Party says all Liberal MPs believe they are in compliance with the Constitution. But of course this is the whole problem: too many MPs believed they were in compliance when they were not. Barnaby Joyce insisted on morning television that he was fine – he’s now out of parliament and running in a byelection. And Turnbull himself said later in the same press conference that, “People sometimes have mistaken beliefs.”

Of course, it’s true, as Turnbull has said repeatedly in recent days, that other MPs may choose to refer their colleagues to the High Court. But this is disingenuous. Turnbull knows there is a convention, aimed at avoiding vindictive squabbles, that MPs do not refer other MPs – they refer themselves, or let their party do so.

In other words, we are talking about a messy, non-binding and ineffective system that will leave us roughly where we are now: with MPs responsible for outing themselves.

And boy, hasn’t that worked well so far?

By this stage, you might have spotted a contradiction in my thinking: if the system is so bad, why do I think it’s likely to lead to the end of the government?

That’s because it does three other things.

The first is – and fair credit to the PM here – that by bringing more information into the public domain it does make it more likely that mistakes are spotted in MPs’ assumptions, and that they come under pressure to quit. They will probably still have to concede all this, and that might not happen – but it is now much more likely to.

What it does at the same time is give the government more control over timing than it currently has. There is a good chance all this will take until next year to sort out. While it is being sorted out, all doubts over MPs can be shelved until the process is complete. That gives the government several more months in which to plan for an election. (This is also a good indicator the government sees an election as very possible.)

The new process also drags Labor into the mess. Even if you accept that Labor’s checking processes are better than the government’s, it’s still unlikely that every single opposition MP will survive. If Turnbull has to go to an election because of citizenship, he needs to be able to point the finger at Labor as well. He will then argue it is not government incompetence but a system-wide problem that is driving events. That argument may or may not work, but you’d rather have it than not.

In the immediate future, Turnbull may get what he wants: for the citizenship noise to quiet. That might allow him to do what he needs to do this year, including finalising same-sex marriage and climate policy. On the other hand, with an election very possibly in the offing, who knows how states, the Opposition, and Coalition MPs will react. Turnbull may have quietened things, or he may have just made them much more interesting than he intended.