Washington  - Democratic Party presidential primary elections got underway Tuesday in the southern state of Kentucky, a few hours ahead of a further primary vote, in the north-western state of Oregon, in the ongoing battle between Senators Hillary Clinton and Barack Obama for their party's nomination.

Clinton, 60, was clearly favoured to win in Kentucky, while the 46-year-old Obama was seen as leading in Oregon, according to the latest polls before the voting.

Even if Clinton were to win both states, she was unlikely to make much of a dent in Obama's overall lead in the delegate count.

Clinton, who represents New York state in the US Senate, is about 200 delegates behind Obama - Senator from Illinois - in the state-by- state primary contests, with 103 delegates up for grabs in Tuesday's vote. After Tuesday, only three more primaries remain until June 3.

A strong showing by Obama on Tuesday would mean he could capture a majority of all delegates for the Democratic nomination, but would still fall short of the 2,025 needed to seal his candidacy for the November 4 presidential election.

"We will have a majority of the pledge delegates," Obama said on ABC television. "Obviously we won't have completed the nomination process, but I think it's an important milestone for our campaign."

Clinton has vowed to fight on until all votes have been counted, pledging to stay in the race at least until June 3, when Montana and South Dakota cast the final ballots of the campaign. (dpa)