Gov. Jan Brewer Friday night pulled the plug on a potential special legislative session intended to counter an overhaul of the state's primary-election system.

Brewer's office blamed lawmakers for backing out on an agreement she had negotiated earlier with them.

"They've lost their nerve, and that's too bad," said Matthew Benson, Brewer's spokesman.

The action, or lack thereof, means the Open Elections/Open Government initiative -- if it qualifies -- will not have to share space on the November ballot with a competing measure.

"That is so awesome!" campaign chairman Paul Johnson said late Friday. He credited the change of course at the Capitol to the spotlight he and other supporters focused on the plans for a fast-track special session.

They had lambasted the Legislature's plan as a transparent power grab by politicians who benefit from the current low-turnout primary elections.

But lawmakers, such as House Speaker Andy Tobin, R-Paulden, said their intent was simply to offer a contrast to the citizen initiative, which they say is fraught with problems.

"We wanted to make a clear distinction," Tobin said, adding he didn't detect any of his House members getting cold feet about a competing ballot measure.

Brewer's office said the deal fell apart in the Senate, hampered by lawmakers either unwilling or unable to return to the Capitol next week. The governor's spokesman had harsh words for the collapse in plans.

"It's infuriating and more than just a little disappointing that legislative leadership urgently requested that the governor go down this road and put her name behind this, and when she does, they have a change of heart," Benson said.

He and Tobin said it's highly unlikely the issue will resurface.

Due to the printing deadline for the ballot's publicity pamphlet, lawmakers were working against a mid-July deadline to refer a question to the Nov. 6 ballot.

Senate President Steve Pierce, R-Prescott, did not return a call seeking comment, nor did his spokesman.

The citizen initiative would create create a primary system in which all candidates for a given partisan office compete against each other, with the top two finishers advancing to a general-election runoff.

Designed to draw Arizona's growing ranks of independent voters to the polls during primary elections, the measure would allow candidates to run without party labels. If a candidate decides to list a party, it would have to match his or her voter registration form.

The option of not listing party affiliation troubled Brewer and some lawmakers.

They worked out an alternative that would have required candidates to declare themselves either as an independent or as a member of one of the four recognized parties: Democrat, Green, Libertarian or Republican.

Although that's the way the current system works, it was important to offer the legislative referral as a counterpoint to the citizen initiative, lawmakers said. That's because voters use party labels to distinguish between candidates.

Benson said party labels signal a candidate's values and philosophy. Brwer is a staunch backer of the partisan-primary system, and likely will speak out against the Open Government initiative if it qualifies for the ballot.

That is likely, as supporters Thursday filed petitions with the signatures of more than 365,000 voters with the Arizona Secretary of State. A total of 259,213 valid signatures is needed to win a place on the ballot.

Some Republican lawmakers wanted to go further with a ballot measure. For example, some liked the idea of a caucus system run by each political party. Others favored requiring a single primary but stipulating that at least one member of each political party advance to the general-election ballot.

But Brewer balked at such sweeping changes, said Senate Majority Leader Frank Antenori, R-Tucson.