PORTLAND, Ore. (AP) — A federal judge last week issued a preliminary injunction blocking Oregon's ban on so-called real estate "love letters" — the nickname for personal notes from prospective homebuyers to home sellers.

In his court order issued last Friday, U.S. District Judge Marco A. Hernández said the law violates the First Amendment of the U.S. Constitution by restricting free speech too broadly, The Oregonian/OregonLive reported.

The conservative Pacific Legal Foundation filed the lawsuit in U.S. District Court on behalf of the Bend-based Total Real Estate Group against Oregon Attorney General Ellen Rosenblum and Real Estate Commissioner Steve Strode, alleging that forbidding the letters violated First Amendment rights.

The letters, often written to appeal to a seller to accept a potentially less-competitive offer, were outlawed as of Jan. 1 by lawmakers seeking to ensure that sellers couldn't make decisions based on race, national origin, marital or family status, sex, sexual orientation or other protected classes.

The judge's injunction was a "major victory for free speech and economic opportunity," said Daniel Ortner, an attorney with the Pacific Legal Foundation, which says it defends "Americans from government overreach and abuse."

The ruling "preserves the opportunity of home-buyers to speak freely to sellers and make the case why their purchase offers should win out," Ortner said in a statement.

The Oregon Real Estate Agency on its website said it will not enforce the law unless a further court order allows it to go into effect. Rosenblum's office didn't immediately respond to an email seeking comment.

Democratic Gov. Kate Brown signed the bill prohibiting the letters last year after it unanimously passed the House of Representatives and passed the state Senate on a mostly party-line vote.

Oregon State Rep. Mark Meek, a Democrat who is also a real estate agent, proposed the legislation. He has said he started to reconsider the practice of personal letters as he became more involved in work to combat housing discrimination.

It's believed to be the first such law in the country.

The National Association of Realtors has said the letters raise fair housing concerns because they often contain personal information and could reveal a potential buyer's race, religion or familial status. "That information could then be used, knowingly or through unconscious bias, as an unlawful basis for a seller's decision to accept or reject an offer," according to a post on the association's website.

The lawsuit said lawmakers provided no proof that such discrimination was taking place and that state and federal laws already prohibit housing discrimination.

Hernández said Oregon's goal was laudable, given its "long and abhorrent history of racial discrimination in property ownership and housing" that for decades explicitly blocked people of color from owning property.

But the bill was overly inclusive, the judge said, banning significant amounts of innocuous speech in love letters beyond references to a buyer's personal characteristics.

Hernández said the state "could have addressed the problem of housing discrimination without infringing on protected speech to such a degree."

The preliminary injunction will remain in effect until Hernández makes a final decision in the case.