Gov. Janet Mills vetoed a bill Wednesday that would prohibit foreign spending on referendum campaigns in Maine, which means the measure will likely go to state voters as a referendum question in November.

The bill, L.D. 1610, “An Act to Prohibit Campaign Spending by Foreign Governments and Promote An Anti-Corruption Amendment to the United States Constitution,” would prohibit businesses and other entities with foreign government influence from participating in the citizen-initiated referendum process through monetary expenditures, Mills said in her veto letter to the Legislature. State law already bars foreign governments from contributing to candidate campaigns.

In addition, the measure would direct the state’s congressional delegation to put forward a constitutional amendment to set campaign fundraising and spending limits across the country.

“While I strongly support and share the desire to find ways to prevent foreign influence in our elections, the language of this bill is too broad and would likely result in the unintended consequences of effectively silencing legitimate voices, including Maine-based businesses, in debates that would impact their interests,” Mills said.

The governor’s veto of a similar 2021 bill sparked a citizen petition effort to force a referendum onto the ballot asking voters to ban foreign spending on campaigns.

Their petition effort was certified by the Maine Secretary of State’s Office, meaning there will be a statewide referendum on the foreign spending question in November unless the Legislature overrides Mills’ veto. Lawmakers are scheduled to reconvene Tuesday to tie up loose ends and to consider any veto overrides. The Legislature could attempt to override the governor’s veto, which would take the support of two-thirds of the House and Senate. The bill passed in the House last month by a vote of 73 to 53.

Supporters of L.D. 1610 expressed outrage at the governor’s veto. The group Protect Maine Elections said the bill gained broad bipartisan support in both the state House and Senate.

“With this veto, the Governor has once again ignored the will of the voters and the legislature and is refusing to protect our elections from foreign governments that wish to disrupt our democracy,”  Sen. Rick Bennett, R-Oxford, said in a statement Wednesday evening. Bennett chairs Protect Maine Elections.

“The opponents of this initiative are few, foreign, and financially unfettered and it’s extraordinarily disappointing that the Governor would succumb to their influence. We cannot let them succeed,” Bennett said. “A referendum election should be considered a backstop for when the Legislature fails to act on an initiated bill. I urge my colleagues to stand with the Maine people and vote to override the Governor’s veto of LD 1610.”

Sen. Nicole Grohoski, D-Ellsworth, also called on legislators to override the veto.

“Free and fair elections are the foundation of our country and our state, and we have the responsibility to ensure that they are conducted of, by and for the people,” Grohoski said in a statement. “Unfortunately, foreign government spending and dark money special interest groups threaten our core institutions. The voters I talk with have had enough.”

Mainers will decide in November whether to replace the state’s two largest electricity companies, Central Maine Power and Versant Power, with a nonprofit consumer-owned utility. If approved, the initiative would establish Pine Tree Power Co., which would buy out investor-owned Central Maine Power and Versant Power and then be responsible for electricity transmission and distribution across most of the state. CMP is owned by Avangrid, whose majority owner is Iberdrola, which is based in Spain.

Pine Tree Power said in a statement Wednesday that it was disappointed that Mills sided with foreign utility corporations.

“Making sure that our elections are secure, fair and free of corruption should be the utmost priority of any democracy,” Pine Tree Power said. “However, our campaign is unsurprised to see that once gain, Governor Mills has chosen to protect massive corporations rather than the Mainers who elected her.”

In her veto letter, Mills said she shares concerns raised by the Maine Press Association and the Maine Association of Broadcasters that L.D. 1610 “would restrict and burden speech about public issues in Maine by forcing news outlets to create an oppressive, time-consuming, and costly self-censorship regime.”

Mills did not rule out supporting future legislation designed to root out dark money and foreign influence on citizen referendum elections by “enacting a more narrowly tailored and easily understood statute.”

“Foreign actors have, and will, attempt to influence elections in America, but in attempting to protect our citizens from such nefarious actors, we should not create a bureaucratic morass that will entrap and silence otherwise legitimate voices and undermine the fundamental cornerstones of free speech and free press,” Mills said.