When the School Reform Commission meets to vote on a school budget tonight, the commissioners will be asked to accept a lot of assumptions. Most notably, the schools would like to assume that they'll get $94 million more from the city of Philadelphia, and about $150 million in union concessions from teachers and other school workers.

Those are the kind of assumptions that many budgets are based on, but these two in particular have become mired in political quicksand. For one thing, the mayor wants the $94 million to come from reforming the property-tax system — a plan that is being met with resistance from both Harrisburg and Council.

And now, the money from union concessions — while always a big "if" — has gotten more complicated with a recent City Council resolution that could hold up the $94 million in funding until a union settlement is reached.

This week, eleven members of City Council backed a resolution, authored by Maria Quinones Sanchez, saying Council should not act on school-budget issues until the schools reach an agreement with SEIU 32BJ, the union that represents district maintenance, cleaning and transportation. All 2,700 workers recently received layoff notices, a serious threat from the district, which has said it needs to get $50 million in savings from them, or else outsource their work.

In other words, don't mess with the union.

In a statement about the resolution, Sanchez pointed out that SEIU members do vital work in the schools, deserve to make a decent living, and are important contributors to the city's economy.

We appreciate that Council may be trying to impose some accountability on money it may give the school district — especially after last year, when Council approved money that was supposedly saving kindergarten, only to learn that then-Superintendent Arlene Ackerman had already made a deal with the state for that money. But we disagree with Council inserting itself in the middle of negotiations between the district and any union.

It's not that Council shouldn't support unions. But by its public declaration of support for the union now in negotiation with the district has given the union much more leverage in the fight. Council has changed the stakes of the negotiation. We think that's a line that shouldn't have been crossed.

Besides, the $94 million that the district is asking from the city is a separate transaction from the savings the district hopes to get from the unions. Council is right to ask for a plan of how that money would be spent — a plan that the district has provided.

The question remains, if Council objects to the district finding big savings in maintenance, cleaning and transportation, where does it propose the schools find money? Should they make other cuts that might impact students even more directly?

The resolution also calls on the state to restore funding for the school district — an idea we enthusiastically support. But we aren't counting on that money, and frankly, we don't see how sending the message that unions will be protected at all costs will persuade Harrisburg of anything.

There are no simple or easy solutions to the district's current problems, and we give Council credit for grappling with this more seriously than in the past. And Council is well within its rights to make sure its priorities are reflected in the district's budget before putting more taxpayer money there. But the Council resolution reduces the options available to the district for preserving its solvency — and, unfortunately, muddies the waters even further.