As it geared up for a two-week strike last fall, the Chicago Teachers Union spent nearly $1.5 million from the dues it collects from members on lobbying and other political activity, a Chicago Sun-Times examination of the clout-heavy union’s finances has found.

That was over the 15-month period between March 2018 and July 2019.

The money was on top of $1.2 million that the CTU’s two political action committees gave union-friendly candidates and political organizations.

And a union foundation has cut back sharply on the money it gave to charities and like-minded groups — to $1 million in 2018 from $1.9 million the previous two years.

That’s according to the Sun-Times’ review of tax and campaign-finance filings as well as documents the union for the first time is required to file with the U.S. Department of Labor. Those offer a more detailed picture than previously has been available to show how the 24,000-member labor group spends its substantial wealth.

The requirement to make that detailed financial filing was triggered by the March 2018 merger of the previously shrinking CTU and the growing union representing teachers at privately managed charter schools.

The new federal reports also provide a clearer picture of: annual losses from rent topping $1 million on the CTU’s previous headquarters at the Merchandise Mart, more than $1.4 million in legal spending on 11 labor grievances, lawsuits and collective-bargaining costs, and the salary of every CTU staffer and the stipend paid to each union delegate.

In addition, the newly required filing contains the names and costs of all CTU contractors and political consultants.

In contrast, its yearly tax filings with the IRS — available through June 30, 2018 — count only union staffers and name only the top-paid employees and vendors. They don’t differentiate between the union’s “representational activities” for members, estimated at about $5.4 million in the Labor Department filing, and the CTU’s political activities.

The IRS documents show that the number of the foundation’s grant recipients fell to 37 in 2018 from 53 the year before, and the average grant to $27,000 from $37,000. Since 2014 when it got an influx of millions from the sale of an apartment tower the CTU had owned for retired teachers in the Gold Coast, the foundation has lost about $2 million a year.

Together, the reports offer a broader picture of a union whose social justice agenda reaches beyond the classroom and teacher pay and benefits, the Sun-Times found.

At the time of the most recent filings, the teachers union had a total of roughly $58 million in its main war chest that’s fueled by members’ dues, its two foundations and its two political action committees.

The union would not make Jesse Sharkey, its president, available to discuss finances.

Some CTU members have grumbled on Facebook about how their dues — a flat $55.85 per pay period — are being spent directly on political candidates. For example, the union put $215,000 into Cook County Board President Toni Preckwinkle’s failed campaign for mayor. The CTU also shifted $56,000 from its budget to the CTU-PAC.

“Can someone please post, again, the way to opt-out of your union dues going to support political candidates?” one teacher wrote on the “Members First” Facebook page of CTU members who have been pushing for more accountability on union spending. The group unsuccessfully ran a slate against the current teachers union leadership.

“That is on the minds of many members who are frustrated with the lack of transparency and accountability in political spending,” another member responded to the Facebook post. “Opting out of PAC voluntary contributions is an option, and sends a message and hopefully brings about change.”

Asked about the union’s political activities, Jennifer Johnson, the CTU’s chief of staff, says the CTU’s work is “inherently political.” But she notes that members can decide whether their dues go to the union’s PACs.

“We’re fighting for public education in a sphere where public education is under the realm of the mayor, who is an elected political leader,” Johnson says. “So you can’t just parse the work that simply.”

Regarding the union foundation cutting nearly in half what it gives to charities and other not-for-profit organizations, Johnson says spending was higher the previous two years — after the foundation was reinvigorated with a $48 million windfall from the sale of the Gold Coast apartment tower — as part of an effort to make an immediate impact before scaling back.

“Over time, [the foundation is doing] the kind of long-term planning to make sure that donations continue, that the foundation is donating effectively and strategically and then making sure that it’s sustainable over time,” Johnson says.

The examination of the union’s finances also found that: