Hillary Clinton last night vowed that she will "never give up" in her battle against Barack Obama after a landslide victory - by a margin of more than two to one - in West Virginia's primary.

Although her win in one of the whitest and most rural states in America failed to loosen Barack Obama's tight grip on the Democratic nomination, she was swift to point out that working class voters had once more turned their backs on her rival.

Mrs Clinton argued that by winning in states such as Ohio, Pennsylvania and now West Virginia, she has demonstrated the strength needed in November's looming general lection contest against John McCain. "This race isn't over yet," she declared. "The bottom line is that the White House is won in the swing states, and I am winning the swing states."

Seeking to stamp on calls for her to pull out before the final primaries on June 3, she added: "I am even more determined than ever to carry on this campaign until everyone has had a chance to make their voices heard."

But she knows Mr Obama remains ahead in every count that matters - elected delegates from primaries and caucuses, the Democratic elite's super-delegates, and the popular vote.

Even if Mrs Clinton won the remaining five contests by the same overwhelming margin of up to 30 points that she ran up in West Virginia, she would still trail Mr Obama by around 100 elected delegates. She is favoured to win Kentucky next week and Puerto Rico next month but her rival is likely to prevail in Oregon, Montana and South Dakota.

Mr Obama is preparing to claim a majority of the pledged delegates after next week's voting in Kentucky and Oregon. And James Carville, Bill Clinton's ultra-loyal former strategist, stated yesterday: “I think the great likelihood is that Obama will be the nominee. As soon as I determine when that is, I’ll send him a [campaign] cheque.”

In her speech in Charleston last night, Mrs Clinton went out of her way to praise Mr Obama and indicate that she was ready to help unite the party ahead of November's looming battle with Republican John McCain.

"I will work my heart out for the nominee of the Democratic Party to make sure we have a Democratic president." She said that they both share a "commitment to bring America new leadership means we have always stood together on the most important issues".

But, in a message to the remaining 200 or so uncommitted super-delegates who represent her last lingering hope of pulling of an against-all-odds victory, she still added: "Tonight, in the light of this overwhelming victory in West Virginia - to everybody still making up their minds, I am in this race because I believe I am the strongest candidate to lead our party in 2008 and the strongest president to lead our nation starting in 2009."

Many superdelegates appear unwilling to go against the will of the delegates elected in primaries. But, to loud cheers, Mrs Clinton told the crowd in the three quarters-full Charleston civic centre: "You will never be counted out, and I won't either. You will not quit, and I won't either."

Mr Obama yesterday sought to brush past his long-anticipated defeat in West Virginia by appearing in the general-election battleground state of Missouri, saying it was a place "where we will compete to win when I am the Democratic nominee for president."

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