By Jason Lange
WASHINGTON (Reuters) - Democratic Senator Gary Peters of Michigan leads his Republican challenger among likely voters, while the North Carolina race between Republican Senator Thom Tillis and his Democratic rival appears to be a toss-up, according to Reuters/Ipsos opinion polls released on Tuesday.
There are about nine competitive U.S. Senate races this year, seven with vulnerable Republican incumbents and two with vulnerable Democrats. To win the Senate, Democrats need to pick up three seats if the party wins the White House and four if not.
Here are the latest results on three Senate races on which Reuters/Ipsos is polling:
MICHIGAN
* 49% of likely voters polled from Sept. 11 to 16 said they planned to vote for incumbent Democrat Gary Peters.
* 43% planned to vote for Republican challenger and businessman John James, with the remaining voters undecided or planning to vote for another candidate.
* 2% said they had already voted.
NORTH CAROLINA
* 48% of likely voters polled Sept. 11 to 16 said they planned to vote for the Democratic challenger, former state Senator Cal Cunningham.
* 44% planned to vote for incumbent Republican Thom Tillis, with the remaining voters undecided or planning to vote for another candidate. Cunningham's 4-point lead is within the poll's credibility interval, making the race in essence a toss-up.
* 4% said they had already voted.
ARIZONA
* Reuters/Ipsos opinion poll expected on Wednesday.
NOTES: The Reuters/Ipsos poll was conducted online and in English. The Michigan poll surveyed 637 likely voters and had a credibility interval of 4 percentage points. North Carolina's surveyed 586 likely voters and had a credibility interval of 5 percentage points
(GRAPHIC: Where Biden and Trump stand on key issues - https://graphics.reuters.com/USA-ELECTION/POLICY/ygdpzwarjvw/index.html)