SEATTLE -

Facing a multimillion-dollar initiative campaign to expand background checks for gun sales, local Second Amendment activists are responding with their own ballot measure.

A coalition of gun-rights groups on Wednesday unveiled Initiative 591, which would prevent Washington state from adopting background-check laws more restrictive than the federal standard.

The initiative would also prohibit any confiscation of firearms without due process.

If supporters get some 246,000 valid signatures, the proposal would become an initiative to the Legislature in 2014 and could end up on the November 2014 ballot -- just like a pro-background-check measure.