Supporters of the new I-1639 gun initiative reached the required 260,000 signatures to get it on the November ballot. The fanfare was short-lived, however, as opponents just announced a lawsuit against the initiative.

“I dropped off the lawsuits today at the Attorney General’s office, the Secretary of State’s office, and also the sponsors of I-1639 and their attorneys,” prolific activist Glen Morgan told KTTH’s Todd Herman. “What it’s saying is that the Secretary of State’s office cannot count the signatures collected over the past month, because the people who sponsored it failed to print the correct language on the back of their initiative.”

Initiative I-1639 would: create enhanced background checks for semiautomatic assault rifles; raise the age to purchase them from 18 to 21; require a firearm safety training course; enact a waiting period before purchasing; and establish standards to responsibly store firearms.

RELATED: I-1639: Washington state’s latest gun control initiative

The lawsuit is being brought by the Second Amendment Foundation and the Citizens Committee for the Right to Keep and Bear Arms. It doesn’t specifically address any of the individual measures, but argues on legal technicalities.

According to the suit, the initiative contains type that is too small to read, and does not show the actual changes to law as the website does, failing to provide “a readable, full, true, and correct copy of the proposed measure printed on the reverse side of the petition.”

Gun initiative has backing of Paul Allen

Months in the making, the initiative arose in the wake of recent school shootings in Florida and Texas, which left a total 27 people dead. The Alliance for Gun Responsibility soon after raised upwards of $3 million for its latest Washington state ballot measure. It also received the financial backing from Microsoft co-founder Paul Allen and venture capitalist Nick Hanauer, who each contributed $1 million.

Allen tweeted about his support, “I hope people throughout the state will support the campaign, so that we can qualify and pass this important initiative into law.”

Proponents have not yet announced how they plan to respond to the lawsuit.

“This is a complete amateur hour screw-up on their part. I don’t know how anybody would be able to explain or justify it,” Morgan said.

“I don’t know how you go back to Nick Hanauer or Paul Allen, who gave you millions of dollars, and say, ‘Oh, I’m sorry. We just didn’t bother to proof the document first.’ I just can’t believe it.”