A new poll shows North Carolina Senator John Edwards increasing his lead over his principal rival, Massachusetts Senator, John Kerry ahead of Tuesday's South Carolina Democratic primary. Mr. Edwards says he must win in South Carolina if he is to stay in the Democratic presidential primary race.

While he remains the overall front-runner among Democrats, Senator John Kerry trails John Edwards in South Carolina.

According a the latest poll in the state, issued by Zogby International, 26 percent of Democrats in the state say they will vote for Mr. Edwards while 22 percent say they support Mr. Kerry. Twenty-two percent of voters in the state say they remain undecided.

The poll shows Mr. Kerry's support slipping slightly in South Carolina, two days before Democrats vote in the first southern state to hold a primary this year. Another poll from cable television network CNN and the Los Angeles Times shows Mr. Edwards with an even bigger lead over Mr. Kerry.

Mr. Edwards, who was born in South Carolina, says he has to win here to remain competitive in the race. Political experts say Mr. Kerry can afford to come in second place here and still maintain his overall lead. Seven states hold primaries on Tuesday.