We knew going into 2011 that there would be three procedural choke points, at which the threat of a government shutdown was quite real. The first was in early April, when funding for the current fiscal year nearly forced a shutdown. The second was the debt-ceiling vote, which was resolved about six weeks ago.

And then there’s the third one, which is coming right up.

Congress only has a few weeks to approve new appropriations bills before October 1 and the end of the fiscal year. As of mid-August, House Majority Leader Eric Cantor (R-Va.) said there was nothing to worry about. He even told his caucus in writing that the debt-ceiling agreement “set a level of spending that is a real cut from the current year level,” and this existing budget framework (a) would avoid a shutdown, and (b) allow Republicans to “enact into law full-year appropriations bills at this new lower level.”

The only thing that could go wrong would be if GOP officials push for cuts beyond the agreed upon levels, and renege on a deal they just struck. Well, guess what.

So much for comity…. In a surprising bit of hardball, House Republicans confirmed that they had been actively considering a plan to tamper with the August budget agreement by cutting even more from 2012 spending in order to put pressure on Senate Democrats to come to terms faster on domestic bills for the coming fiscal year.

Instead of the agreed-upon appropriations target of $1.043 trillion, a stopgap continuing resolution or CR this week would be calibrated at a lower $1.035 trillion level. The idea — promoted by Speaker John Boehner — was to effectively withhold about $8 billion for the first two months of the fiscal year, with the money becoming available only as Senate Democrats come to terms with the House on the dozen annual spending bills that cover government operations.

It’s hard to say at this point where all of this is going, and how much of this is just more posturing from the Speaker’s office (or rank-and-file members pressuring the Speaker’s office). Maybe it’s some kind of trial balloon; we’ll know more over the next 48 hours.

But I mention this because the odds of a government shutdown in a few weeks have gone from zero to, well, let’s say non-zero. Would Boehner break the terms of an agreement he struck just last month? Would do the exact opposite of what Eric Cantor said House Republicans would do just two weeks ago? Apparently, it’s possible.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.