A proposal heading to the governor will give candidates an option for getting on the primary election ballot if they fall short at a political party nominating convention.

Unless the legislation is signed into law, it's possible that some candidates in this year's crowded congressional races could be squeezed out at Democratic and Republican preprimary nominating conventions in mid-March.

The bill won final approval in the Legislature when it passed the House 65-1 on Tuesday. It previously cleared the Senate.

Candidates for the U.S. Senate, U.S. House and other statewide offices can earn a place on the June primary ballot only if they receive at least 20 percent of the votes of delegates at their party's preprimary nominating convention.

Previously, candidates who missed that 20 percent threshold still could get on the ballot by submitting additional nominating petitions to the secretary of state. That option was eliminated last year by a change in law, however.

The bill heading to Gov. Bill Richardson will return the system to the way it was before last year's change.

The governor's office did not immediately respond Wednesday to a request for comment on the legislation. The governor will have until early March to decide whether to sign or veto the measure.

One congressional candidate, Democrat Don Wiviott of Santa Fe, filed a lawsuit last month challenging the preprimary nominating convention law. He contended it unconstitutionally restricted ballot access for candidates.

Wiviott is among six Democrats seeking the party's nomination in the 3rd Congressional District. Two Republicans are running for the seat being vacated by the incumbent, Democrat Tom Udall.

No incumbents are seeking re-election in New Mexico's three congressional districts. Instead, they are running for the U.S. Senate seat being vacated by Republican Pete Domenici.

Tuesday was the filing deadline for Democrats and Republicans in congressional and statewide races.

Seven candidates — five Democrats and two Republicans — filed for the Albuquerque-area 1st District seat and 10 candidates — four Democrats and six Republicans — are running in the 2nd District of southern New Mexico. Independents and minor party candidates file for office later this year.

Wiviott applauded the Legislature for approving the preprimary nominating convention measure.

"This fix will ensure our elections are a contest of ideas, not a competition among a few," Wiviott said in a statement. "With so much at stake in this election, voters deserve to hear from a full range of voices. Now they will."

The preprimary nominating convention bill is Senate Bill 1.