Political Sniping Season Opens : Congress: The release of a confidential poll showing Cunningham favored over Lowery for the 51st District fuels their feud.

The release of a confidential poll showing Rep. Randy (Duke) Cunningham favored over Rep. Bill Lowery by GOP voters in the recently redrawn 51st District has all but guaranteed that the two Republican incumbents will confront each other in a bruising primary battle that party leaders had diligently tried to avert.

The poll, commissioned by the National Republican Congressional Committee and the subject of closed-door meetings with the House GOP leadership Wednesday and last week, shows the freshman Cunningham leading six-term Lowery 36% to 31% in the North County district.

The release of the poll by Cunningham’s office late Wednesday virtually swept away any possibility of heading off the contest between the two incumbents. The period for candidate filing opens Monday, and spokesmen for both candidates said they will pick up the necessary paperwork that day. Candidates have until March 6 to complete the filing.

Consistent with the tense relations between the two members, going public with the poll caused immediate controversy.

Cunningham said Thursday that, before releasing the poll information, he talked with several members of the GOP leadership.

“I had the release in my hand,” Cunningham said. Minority Whip “Newt Gingrich said, ‘Check with (Secretary of the House Republican Conference) Vin Weber.’ I checked with Weber and he said he had no problem with it.”

But other members of the House leadership said the ground rules were clear: Both the meetings and poll data were to remain strictly confidential.

“I consider this a fundamental violation of what we agreed on,” said Rep. Jerry Lewis (R-Redlands), chairman of the House Republican Conference. The leadership “was trying to be very neutral . . . and got a commitment from both sides that they would cool it. I really have to question this level of professional conduct.”

Michelle Tessier, a spokeswoman for House Minority Leader Robert H. Michel (R-Ill.), said that “it was (Michel’s) understanding that the discussion and numbers were meant for in-house discussion only.”

The intent of releasing the data, Cunningham said, “was to show (Lowery) was wrong to say he could not win in the 49th and that he could beat me in the 51st.”

The recently redrawn 49th District contains the coastal communities where Lowery ran poorly in his last election.

Early in January, Lowery’s office circulated a memo saying that a poll of 250 Republicans in the 51st District showed Lowery beating Cunningham “by a large margin”--but no specific numbers were offered.

Against that backdrop, Cunningham and his advisers said they felt compelled to release the poll data, surmising that it would have been Lowery’s office jumping the gun had the survey been more to his liking.

On Thursday, Lowery termed the release of the data “outrageous.”

“Based upon this violation of trust with the House GOP leadership, he has shattered any attempt at resolving this,” he said.

Lowery had no comment on the poll data itself, other than calling it “inconclusive.”

“We had hoped (the poll would show) that there was a clear favorite, but it was a wash,” he said.

The poll shows that in a head-to-head primary, Cunningham would beat Lowery in both the recently redrawn coastal 49th District, 38% to 30%, and the North County 51st District, 36% to 31%.

According to Cunningham, the poll reveals that Lowery “can win against any Democrat in the new 49th District,” although the findings actually show Lowery in a dead heat against “any” Democrat, 39% to 39%.

In the 51st District, the poll shows Lowery beating a Democrat more handily, 53% to 28%.

Against a Democrat, Cunningham trailed in the 49th District by a 37-39 margin, the poll shows, but was ahead, 50-26, in the 51st.

According to Mark Strand, Lowery’s administrative aide, the margin for error in the poll is 8% for the head-to-head primary and 5.8% for the other questions. That means that in an actual election, the results would be expected to be within 8 points and 5.8 points of what the poll found. Strand said the poll is only an unscientific “snapshot.”

The decision to conduct the poll had been hammered out by the House leadership at an earlier meeting with the San Diego delegation last Wednesday.

“The two sides could not agree on what questions to ask,” Lewis said, “and the poll became so general that it became a useless tool.”

“It was structured in such a way that anyone could put whatever spin they want to on the numbers,” said Lewis, whom Cunningham described as a “100% Lowery backer.”

Lowery sits on the Appropriations Committee and is the ranking minority member of the Military Construction Subcommittee.

Cunningham, the former head of the “Top Gun” naval fighter pilot training school at Miramar Naval Air Station, is on the Armed Forces Committee.

Times staff writer Alan C. Miller contributed to this article.