When legislators try to take control over a part of the lawmaking process that today involves the executive branch, fans of governmental checks and balances should be on alert.

That’s what’s afoot at the Minnesota Legislature, which will return Tuesday for the final six weeks of this year’s budget-setting session. Both the Republican House speaker and the DFL Senate Majority Leader are sponsoring bills that would give the Legislature more control over calculations of the cost of its own bills — a task now assigned to Minnesota Management and Budget (MMB) in the executive branch.

The bills sponsored by Majority Leader Tom Bakk and Speaker Kurt Daudt aren’t identical. Bakk’s would create a new office to forecast costs, while Daudt’s would assign that task to the Office of the Legislative Auditor.

But in both cases, the offices would report to panels of legislators. And legislators have plenty of personal and partisan self-interest in the numbers that are attached to the bills they sponsor. The changes Bakk and Daudt propose appear to put temptation to bend those numbers within easier legislative reach.

Of course, that’s not the stated goal for removing responsibility for the forecasts, known as “fiscal notes,” from the dozen nonpartisan MMB civil servants who bear it now. But the stated justifications for the change aren’t compelling.

Legislators are always prone to grousing about fiscal notes that are bigger, smaller or slower than they desired. But they can point to no evidence of politically motivated tampering with those numbers or their timing by the executive branch. No such mischief was discovered in a 2011-12 review by the legislative auditor’s office. The auditor’s recommendations for more explanation of assumptions, more information about cost estimate ranges and accommodation of legislators’ desire for private notes for bills not yet introduced have all been adopted by MMB.

If legislators want more timely fiscal notes, they can enlarge the staff that produces them. If they want analysts to better understand their bills, they can allow analysts more time for research. If they want more information about analysts’ conclusions, they can ask.

Reassigning fiscal notes to the legislative branch would cost more, since the MMB analysts who do this work for several months of the year would still be needed for their year-round jobs managing state agency budgets. In fact, the change could result in dueling estimates of the cost of legislation, since the state agencies would still need their own analyses of new bills for the sake of their own budgeting. That kind of conflict would add fuel to legislative budget battles.

From a good-government standpoint, the downside risk appears to outweigh the upside potential in this proposed change. Of course, it’s possible that legislators aren’t looking at this from a good-government perspective. That’s why Minnesotans who do should watch and weigh in.