OLYMPIA – A campaign to tighten Washington’s gun laws turned in petitions with more than 267,000 signatures Thursday and planned to submit more signatures Friday. Opponents of the proposal said they plan to return to court in an effort to block it.

Without the usual fanfare, someone from the company that was paid to gather signatures unloaded nine boxes of petitions for Initiative 1639 from the back of a Jeep and rolled them into the secretary of state’s office. The man, who refused to give his name to reporters, provided staff with paperwork saying the boxes held a total of 267,700 signatures.

An initiative needs at least 259,622 valid signatures from registered voters, and campaigns often have 10 percent or more of their signatures invalidated because of various problems. The I-1639 campaign said it has more than 360,000 signatures total and will submit the rest on Friday in conjunction with a news conference.

Initiative 1639 would place new restrictions on the sale and ownership of all semi-automatic rifles, including raising the age of purchase to 21, requiring completion of a firearms safety training course within the past five years and a more comprehensive background check. It also requires firearms to be placed in locked storage or have trigger locks when not in use in homes. (Editor’s note: An earlier version of this story incorrectly said the new regulations would be limited to military-style rifles, due to a reporter’s error.)

Last week, opponents asked the Washington Supreme Court to order the secretary of state to refuse to accept petitions for I-1639, contending that the print on the petitions was so small it was hard to read and the proposed changes to the law were not properly shown. A court commissioner ruled, however, that opponents do not have the right to keep petitions from being accepted if the secretary of state rules they are valid.

Opponents can raise their criticisms during the campaign, Commissioner Michael Johnston said Tuesday.

Alan Gottlieb, a member of the Second Amendment Foundation – one of the groups seeking the court order – said opponents will cite those deficiencies again when they return to court for a second attempt to keep I-1639 from the ballot.

They will claim the petitions did not present a “true and correct” printing of the initiative, as required by law, and ask the court order to block it, Gottlieb said. The lawsuit will be filed “very shortly,” he said.

Courts are usually reluctant to keep an initiative which has sufficient signatures from going to voters. If that is the case with I-1639, gun-rights advocates will “mount the biggest grass-roots campaign we can against it,” Gottlieb said. If it passes, they will mount a post-election challenge against it.

Tallman Trask, a spokesman for the campaign, said a “Hail Mary, last ditch” effort by Gottlieb and other opponents to keep the initiative off the ballot would not be a surprise.

“They have a habit of being litigious. I don’t expect them to stop now,” Trask said.