KANSAS CITY Kan. (Reuters) - A Kansas Democrat has asked the state Supreme Court to order his party to name a new U.S. Senate candidate for the November election after the court ruled the name of a county prosecutor who withdrew must be removed from the ballot.

Chad Taylor's withdrawal is seen as boosting the candidacy of independent Greg Orman, who is trying to unseat Republican U.S. Senator Pat Roberts in a nationally watched race that could help decide which party controls the chamber.

Republicans seeking to take control of the U.S. Senate have been counting on a Roberts victory. Taylor's withdrawal leaves Roberts and Orman as the main candidates and a victory by the independent would hurt Republicans.

David Orel, in a petition filed late Thursday and circulated by the court on Friday, asked the justices to compel Kansas Democrats to replace Taylor so he can vote for a candidate from his party. He said this is required by state law.

Orel's position is the same as that of Kansas Secretary of State Kris Kobach, a Republican, who said on Thursday he was requiring Democrats to replace Taylor on the ballot by Sept. 26 and was considering legal options if they do not.

In ruling on Thursday that the state must remove Taylor from the ballot, the state Supreme Court sidestepped the question of whether Kansas law required Democrats to replace him.

Orel, who had filed a paper in support of Kobach in the case, said in court papers he is a registered Democrat who voted in the primary and intends to vote for a Democratic candidate in the general election.

Orel's son, Alexander Orel, is a field director for the re-election campaign of Republican Kansas Governor Sam Brownback, campaign spokesman John Milburn said.

Alexander Orel's job with Brownback had no bearing on his father's petition, said Thomas Haney, David Orel's lawyer.

Roberts has accused Democrats of conspiring with Orman, while Taylor has said Kobach's attempts to keep him on the ballot after his Sept. 3 withdrawal were politically motivated. Kobach denied politics played a part.

Kobach had ruled that Taylor did not properly withdraw from the election and could not be removed from the ballot. Taylor appealed that decision to the state's high court.

Representatives of the Kansas Democratic Party did not return calls for comment on Friday.

(Reporting by Kevin Murphy in Kansas City; Editing by David Bailey and Mohammad Zargham)