From Wikipedia, they say it was Neil Kinnock, Blair's predecessor.
Quote Originally Posted by Wikipedia
Controversy broke Biden's candidacy for the U.S. presidency in the 1988 Presidential campaign. He ended his presidential campaign on September 23, 1987 after being accused of plagiarism. Most damaging was being caught on video repeating, with only minor modifications, a stump speech by British Labour Party leader Neil Kinnock. “Why is it that Joe Biden is the first in his family ever to go a university? Why is it that my wife . . . is the first in her family to ever go to college? Is it because our fathers and mothers were not bright? . . . Is it because they didn't work hard? My ancestors who worked in the coal mines of northeast Pennsylvania and would come after 12 hours and play football for four hours? It's because they didn't have a platform on which to stand.” It seems his wife was not the first in her family to attend college and Biden's father actually sold cars. Biden didn't actually say his father was a miner, and after Biden withdrew from the race it was learned that he had correctly credited Kinnock on other occasions. But in the Iowa speech that was recorded and distributed to reporters (with a parallel video of Kinnock) by aides to Michael Dukakis, the eventual nominee, he failed to do so. Dukakis fired the senior aides responsible, but Biden's campaign could not recover.

Biden was also accused of committing plagiarism while a freshman at Syracuse University Law School in 1965. He had received an “F” in an introductory class on legal methodology for writing a paper relying almost exclusively on a single Fordham Law Review article, which he had cited. Biden was allowed to repeat the course and passed with high marks. After ending his Presidential campaign Biden requested the Board of Professional Responsibility of the Delaware Supreme Court review the issue. The Board concluded on December 21, 1987, after Biden had withdrawn, that the senator had not violated any rules, although Biden did not release this result until May 1989.