Citing the disputed vote in a Florida congressional district, a Democratic lawmaker on Wednesday urged Congress to approve his measure requiring a paper trail for electronic voting.

Rep. Rush Holt, sponsor of the bill, said the inaccuracy of electronic touch-screen voting machines "poses a direct threat to the integrity of our electoral system." The New Jersey congressman argued the Florida district, in which more than 18,000 votes have gone uncounted, has exposed the system's flaws.

Florida law requires a recount in all five southwest Florida counties in the 13th Congressional District. But scrutiny is focused on Sarasota County, where touch-screen voting machines recorded that 18,382 people — 13 percent of voters in the Nov. 7 election — did not vote for either Republican Vern Buchanan or Democrat Christine Jennings, despite casting ballots in other races on the ballot. That rate was much higher than other counties in the district.

Rep. Robert Wexler, D-Fla., said he found it "unfathomable" that more than 18,000 people would cast votes in other races but not in the congressional race. He added there's a host of theories that could explain what happened to those votes, but without a paper trail no one knows the truth.

At a news conference with Holt, Wexler blamed Florida's lack of a paper trail law on the "irrational stubbornness of Gov. Jeb Bush," who he says has refused to consider any such regulation.

An unofficial recount of the five Florida counties on Wednesday showed Buchanan with a 401-vote lead over Jennings in the race. The Associated Press' unofficial election night count had the total at 373. Buchanan has declared victory; Jennings has not conceded. The race is one of a handful of races across the nation that remained unresolved in the days after Election Day.

Republican Rep. Katherine Harris, the woman at the center of the disputed 2000 presidential election, has represented the House district. She did not seek re-election to make a bid for the Senate, which she lost.

Holt contended that even after the votes are recounted and a winner declared the absence of a voter-verified paper trail will fuel doubts about the results.

Holt also said at least one electronic voting machine in New Jersey's Ocean County counted votes twice, and some were also added to vote totals for the Senate, county freeholder and county sheriff races in Lakewood, according to a published report.

Holt's "Voter Confidence and Increased Accessibility Act" had the support of 219 House members before last week's election and now has 221 bipartisan co-sponsors, his office said.

The bill would require that all voting systems produce a voter-verified paper record for use in manual audits; ban the use of undisclosed software and all wireless and concealed communications devises in voting systems; and establish procedures to be followed if there is a discrepancy between reported results and audit results.