In case you needed further proof of how enormous the stakes are in the Ohio labor fight for national conservatives, consider this: Right wing groups are pouring over $2 million into TV ad campaigns in the final few days of the fight, I’m told.

National conservative groups view the showdown over Issue 2 — a referendum on Governor John Kasich’s law rolling back bargaining rights — as the central front in their drive to break labor’s back in the middle of the industrial heartland. Polls show that labor is poised to win this fight, though union operatives aren’t all sanguine.

Now I’ve obtained a breakdown of the amounts these conservative groups have spent to book airtime through next Tuesday, when the vote is set to take place. Will Robinson, the media consultant for the labor-backed We Are Ohio, says he got the numbers from the TV stations, and agreed to go on record with them:

* Building a Better Ohio — the leading conservative group in the Ohio battle that is partly bankrolled by private sector interests — has booked a total of $1.8 million in Ohio broadcast and cable time from November 2-8.

* Restoring America — a shadowy group which is reported to have been funded by a single donor during a recent battle in Kentucky — has booked $448,000 in Ohio broadcast and cable time from November 3-8.

* Citizens United, the well-known conservative group, has booked a total of $101,070 in Ohio broadcast and cable time from November 4-8. (A group spokesman confirmed the figure.)

That’s a total of over $2.2 million. Meanwhile, a source close to labor’s We Are Ohio says the pro union forces have booked around $1.8 million in air time, which means they may get outspent by at least half a million in the final stretch. (These numbers are in flux and may not tell the whole story; if I learn more about any spending on either side, I'll update you.)

There’s more. Andy Kroll reports that in addition to TV ads, mailers from conservative groups are blanketing the state, including ones that use debunked statistics to portray public workers as greedy and overpaid.

The last minute flood of spending is testament to the enormous significance of the fight for both sides. Both view it as a referendum on labor’s strength — and on the overall political atmosphere — in a key industrial swing state heading into 2012. For labor a victory would be particularly satisfying: It would challenge the right’s preferred narrative, which holds that the failure to take back the state senate in Wisconsin signaled that labor is headed for irreversible decline and that the conservative drive to break unions is on the march all over the country.