WASHINGTON (AP) _ This is no hurry-up speech. President Clinton has been testing it, refining it and rehearsing it for months before living room audiences, in big auditoriums and at presidential news conferences.

It's the valedictory address of his presidency, boasting of his achievements, and a political testimonial for his hoped-for successor, Vice President Al Gore. After last week's Republican convention, it also will be an answer to George W. Bush's jabs and barbs.

Clinton will speak Monday night at the opening of the Democratic National Convention in Los Angeles as he relinquishes the party's leadership, making the case why Gore should be president and carry on the legacy of the Clinton-Gore administration.

White House spokesman Joe Lockhart said Clinton will use the speech to ``reflect and highlight the extraordinary achievements over the last eight years,'' with credit to the president, the vice president and the American people in general.

``He'll try to discuss what's at stake as far as the choice that faces the American public going into the future,'' Lockhart said Wednesday. ``The president believes ... that we have a clear and very distinct choice this year between building on the success of the last eight years or taking us in another direction, a direction he believes is a U-turn back to policies that have failed in the past.''

Clinton will speak after his wife, Hillary, addresses the convention, and he'll give her Senate campaign a boost. He will be addressing his most loyal, loving audience _ Democrats who have been with him through two elections, scandal and impeachment. Always a spellbinding speaker, he can be assured of a wild reception in his final convention.

Clinton's appearance poses a problem for Gore, struggling to escape the president's shadow and stand on his own. The president enjoys strong popularity in his final months in office while Gore is still trying to introduce himself to the nation and trails in most polls in his race with Bush. Clinton-Gore allies insist that the president will not upstage the vice president.

``The president's speech, while important, will not be vital to the convention, anymore than Ronald Reagan's was in 1988,'' said former Clinton adviser Paul Begala. ``The whole convention turns on Al Gore's speech.''

By agreement between the White House and Gore campaign, Clinton will leave Los Angeles the morning after he speaks. En route home, Clinton will stop in Michigan to appear with Gore, en route to the convention. Two days later, Gore will accept the Democratic presidential nomination.

Clinton has previewed his address in dozens of speeches.

``We've had a lot of vice presidents, a lot of vice presidents made great presidents _ Thomas Jefferson, Teddy Roosevelt, Harry Truman, Lyndon Johnson. But we've never had a vice president that did so much good as vice president as Al Gore _ never, not ever in the history of the country,'' Clinton told the NAACP convention last month.

Frequently, Clinton says, ``There are four things that you need to know about Al Gore.'' The first thing is that Gore has been the best vice president. No. 2, ``He's got a good economic policy.'' No. 3, he is interested in science and technology and ``understands the future.'' And No. 4, Gore ``wants to take us all along for the ride ... blacks and whites and browns, the abled and the disabled, straights and gays, everybody that will work hard, play by the rules, obey the law, do their part.''

Clinton's chief speechwriter, Terry Edmonds, said, ``The major message is, `We've had eight solid years of progress in America on the economy, on the social fabric of the country coming together, the issues of race _ so things are good.

'``The people who did it, who led this, in addition to the American people, are Bill Clinton and Al Gore. So Gore's in the best position to keep that progress going,''' Edmonds said.

White House aides fumed at Bush's charge that Clinton and Gore let the country drift, failing to take advantage of America's prosperity to fix problems.

``He will definitely lay out the record which in itself refutes that,'' Edmonds said. ``The facts refute that.''

Will Clinton take on Bush directly? ``My intuition is not in a harsh or vitriolic way but contrasting the choices and the differences,'' Edmonds said.

Clinton's speech is still taking shape.

``This is one of those speeches where the president will do a lot of the final writing and editing himself,'' Edmonds said. ``We've produced a first draft and he's looking it over. We'll be working on it probably up until Monday night.''