Democratic voters who were given the wrong ballot in a tight race that could force a 50-50 split in Virginia's House of Delegates said Monday in an appeal brief that their disenfranchisement is far worse than a garden-variety election error.

The voters, backed by a law firm aligned with Democrats, filed papers Monday with the 4th U.S. Circuit Court of Appeal in Richmond making their case for a new election in the 28th district.

Republican Bob Thomas beat Democrat Joshua Cole by 73 votes, but elections officials say 147 voters received the wrong ballots. Specifically, 86 people who should have voted in the Fredericksburg-area district were given ballots for a different House race. An additional 61 voters cast ballots in the 28th when they should been assigned to another district.

A judge in Alexandria rejected the request on Friday, saying the ballot errors amount to "garden-variety irregularities" that don't justify federal intrusion into Virginia's election process.

In their appeal, the voters say the errors make it impossible to know the true winner, and rejected the notion that they're too insignificant to merit a new election.

"Instead, these severe problems — which may have tipped the election — reflect a 'patent and fundamental unfairness' with the electoral process," the voters' lawyers wrote.

The appeals court gave the opposing side until Monday afternoon to respond — an expedited schedule that the voters' lawyer, Marc Elias, said is a good sign the court takes the issue seriously.

Barring federal intervention, Thomas would be sworn in when the new legislature convenes on Wednesday.

Republicans have held a 66-34 advantage in the House. Democrats picked up 15 seats in the November elections but need one more to force the power-sharing that would result from a 50-50 tie in the chamber. Democrats lost an opportunity when elections officials drew a Republican's name out of a bowl to break a tie vote in the 94th District race in Newport News.