US Democratic candidate Howard Dean says he will quit the race for his party's nomination if he does not win this month's primary in Wisconsin.
Dean is hoping to break his losing streak
Mr Dean was once the front-runner among Democratic presidential contenders - but he has failed to win any of nine state contests held so far.
The current front-runner, Senator John Kerry, is expected to win easily in Michigan on Saturday.
Mr Dean is focusing on Wisconsin, where he is planning to launch a TV campaign.
The former Vermont governor made the statement as part of an appeal for donations to fund his television ads.
"The entire race has come down to this: We must win Wisconsin," Mr Dean wrote in an e-mail message to supporters.
"Anything less will put us out of this race," the former Vermont governor added.
Mr Dean has spent $40m on a gamble that he could secure the nomination with early victories in Iowa and New Hampshire.
But both states were won by Mr Kerry - who is seen by many Democrats as the best candidate to run against President George W Bush in the November election.
Kerry is clearly ahead of the Democratic pack
In his appeal Mr Dean asked supporters for $50 contributions, in an effort to raise $700,000 to pay for advertising in Wisconsin - which hold its primary on 17 February.
"We must launch our new television advertisement on Monday in the major markets in Wisconsin," he said. "To do that I need your help."
"All that you have worked for these past months is on the line on a single day, in a single state," the e-mail said.
Wisconsin is regarded as a liberal state.