A CITY OF MILWAUKEE Election Commission worker processes absentee ballots for Wisconsin’s primary election April 8, 2020, in downtown Milwaukee. (Mark Hoffman/Milwaukee Journal-Sentinel via AP, file)

MADISON, Wis. (AP) — A federal judge ruled Monday that absentee ballots in battleground Wisconsin can be counted up to six days after the Nov. 3 presidential election as long as they are postmarked by Election Day.

The highly anticipated ruling, unless overturned, means that the outcome of the presidential race in Wisconsin likely will not be known for days after polls close. Under current law, the deadline for returning an absentee ballot to have it counted is 8 p.m. on Election Day.

Democrats and their allies sued to extend the deadline in the key swing state.

U.S. District Judge William Conley granted a large portion of their requests, issuing a preliminary injunction that was expected to be appealed all the way to the U.S. Supreme Court. He put the ruling on hold for seven days to give the other side a chance to seek an emergency appeal.

President Donald Trump won Wisconsin by fewer than 23,000 votes in 2016. Polls show Democrat Joe Biden with a slight lead, but both sides are expecting another tight race. Biden wrapped up a campaign stop in northeast Wisconsin about an hour before the ruling was released. Trump held a rally in the state last week.

The Republican National Committee, the Wisconsin GOP and Wisconsin’s Republican legislators argued that current absentee voting regulations should be left in place, saying people have plenty of time to obtain ballots and get them back to clerks by Election Day.

The Democratic National Committee, the state Democratic Party and groups including the League of Women Voters and Disability Rights Wisconsin filed a series of lawsuits to make absentee voting and registration easier so people won’t have to go to the polls and risk catching the coronavirus.

Conley, an appointee of former President Barack Obama, also agreed with Democrats to lift the Oct. 14 deadline for by-mail and electronic voter registration. The judge extended it until Oct. 21.