The nationally watched contest, one of the most expensive and contentious congressional races this year, is among a handful of House races still contested Monday — six days after the elections.
A partial recount of ballots over the weekend left Mr. Murphy with a lead of 50.3 percent of the vote and a margin of 0.58 percent — just above the half-percent needed to avoid an automatic recount of all votes. A few overseas and military ballots remain outstanding, but under state law the decision for a recount is based on the weekend recount.
The West campaign called the recount a “sham” and complained that a decision by St. Lucie County elections officials to only recount ballots from three days of early voting was insufficient and left open many questions.
“We are after the truth of what votes were cast by voters in St. Lucie County, and the conduct of the canvassing board today casts doubt on their reported numbers,” said statement from the West campaign issued Sunday. “The [election’s] supervisor and the board continue their attempts to hide the facts.”
The Murphy campaign issued a statement after the recount saying it was “now time to put the campaign behind us.”
The courts now appear to be Mr. West’s only option to continue his fight. Under state law, he can contest the election if misconduct or fraud changed the result.
West campaign manager Tim Edson said the congressman “will pursue every legal means necessary to ensure a fair election.”
The candidates and their allies had bombarded the South Florida airwaves with some of the most aggressive attack ads shown anywhere during the campaign season.
Mr. West repeatedly has slammed Mr. Murphy over the challenger’s 2003 arrest in connection with a disturbance outside a South Florida nightclub when he was 19. The Democrat’s arrest mug shot and a link to his arrest report is displayed on a West campaign website.
The Democrat hit back with a TV ad challenging the incumbent’s military record, accusing the Republican of criminal activity in an incident regarding an Iraqi prisoner.
More than $17 million was spent on the race by the candidates and their allies — the third most of any House contest in the country, according to OpenSecrets.org, an independent website that tracks campaign spending.
In another race too close to call, Democratic Rep. Ron Barber of Arizona has pulled ahead of Republican Martha McSally by almost 700 votes after the challenger held an edge by less than 500 votes in the days immediately after the election.
Mr. Barber assumed office in June after winning a special election to succeed former Rep. Gabrielle Giffords, who resigned after suffering serious injuries during an assassination attempt in January 2011. Mr. Barber was an aide to the former congresswoman.
Elsewhere in Arizona, The Associated Press on Monday declared Democrat Kyrsten Sinema the winner over Republican Vernon Parker in a bitterly fought race for a new a newly created Phoenix-area House district. She will be the first openly bisexual member of Congress.
Ms. Sinema, a former state senator, had a narrow lead on election night that made the race too close to call. But she slowly improved that advantage as more ballots were tallied in recent days, and now has an almost 6,000-vote edge that is too much for her opponent to overcome, AP says.
In California, Democrat Ami Bera increased his lead over GOP Rep. Daniel E. Lungren to almost 1,800 votes. The challenger led the longtime incumbent by fewer than 200 votes late last week.
The race for the Sacramento-area district, which is nearly split between registered Democrats and Republicans, was among the most fiercely contested in the nation, and attracted more than $8.3 million in spending by outside groups.
In Utah, Democratic Rep. Jim Matheson appears to have won a tight race over GOP challenger Mia Love, who conceded defeat. But with only about 2,600 votes separating the two and some provisional and mail-in ballots yet counted, major news outlets haven’t called the race.
In another race too close to call, California Democrat Scott Peters increased his lead over seven-term Republican Rep. Brian P. Bilbray to more than 1,300 votes. And in North Carolina, Democratic Rep. Mike McIntyre holds a 420-vote lead over Republican challenger David Rouzer.
In Louisiana, the race between two sitting GOP House members, Reps. Charles W. Boustany Jr. and Jeffrey M. Landry — pitted against each other because of redistricting — will extend a few more weeks as the two were forced into a runoff election after neither got a majority victory.
This article is based in part on wire-service reports.