LONDON -- In a stunning ending to the closest-fought general election here in years, Britain's voters poured out in large numbers yesterday and gave Prime Minister John Major a mandate to govern the country for the next five years.

It was a remarkable come-from-behind performance by the mild man from London's rough Brixton neighborhood, especially because the country is in the midst of the longest recession since the 1930s and discontent with the government's handling of the economy is widespread.

Early this morning, Mr. Major claimed victory. "We've won tonight a magnificent victory, a victory that many people thought was beyond ur grasp," he told cheering supporters at party headquarters.

Separately, the Labor Party's leader, Neil Kinnock, conceded defeat. "Now the Conservatives will continue with the decline," he said in delivering a sweeping condemnation of the government's record.

Other Labor officials appeared dazed.

"I simply don't know how the British mind and the British psyche works to produce these results," said Roy Hattersley, deputy to Mr. Kinnock.

Jeffrey Archer, a high-ranking Conservative and adviser to Mr. Major, borrowed the comment of a person he had encountered " during the campaign to explain the behavior of his party's voters: "The fact we're cross with you doesn't mean we're not going to vote Conservative."

Of Mr. Major he said: "He's very much his own prime minister now. No longer a caretaker. Very much in charge."

Former Prime Minister Margaret Thatcher exulted: "I'm very pleased. Everything we have done in the last 13 years will now be conserved and built on in the future."

Mr. Major took over the party from Mrs. Thatcher, who resigned 16 months ago in the face of a party revolt.

For the past 10 days, he had been consigned to history's dustbin by commentators and political experts, even by many friendly to the Conservatives.

Mr. Kinnock had been so certain of victory that many said he had begun acting like a prime minister.

But it was Mr. Major's certitude of victory that in the end proved the truest. Late in the campaign he took to a soap box to get his message across that Labor was not the right party to govern Britain and that the Conservatives deserved another term.

What he got was a fourth consecutive victory for the Conservatives over Labor since 1979, when Mrs. Thatcher led them into 10 Downing Street, the prime minister's official residence. No British politician had led his party to a fourth consecutive term since Lord Liverpool in 1822.

Early today, the British Broadcasting Corp. projected 334 seats for the Conservatives, a 35-seat drop from the last Parliament but 8 more than the minimum required for a majority in the House of Commons; 273 for Labor, an increase of 42; and 19 for the Liberal Democrats, a drop of three.

Glenda Jackson, winner of two Academy Awards, triumphed for Labor in the north London district of Hampstead and Highgate.

Throughout the campaign, Mr. Major had insisted that his party would avoid the defeat predicted by both the polls and many media commentators, and he managed to fight off Labor's appeal to the electorate for a change.

So powerful was that message that even the Financial Times, the newspaper whose readers constitute the elite of the Conservative constituency in the business world, came out in support of Labor.

It is common for party leaders to predict only victory, but Mr. Major truly believed it. Whether this confidence will redeem him in the eyes ofhis party mandarins -- the men who threw Mrs. Thatcher out and put him in her stead -- is not certain. He did, after all, lose much of the party's large majority.

But as the results unfolded, there was nothing but praise for the 49-year-old party leader from his own ranks. "It is a good night for the Conservative Party," said Kenneth Baker, the home secretary. "It is a good night for John Major."

Most commentators had predicted a hung Parliament, in which no party wins an overall majority of seats in the House of Commons. Beyond the final count, there were several definitive outcomes. Perhaps the most important, for Britain's political health, the country once again has a genuine multi-party system, for while the Conservatives won, their majority of 88 seats was seriously reduced.

The election thus put an end to the overwhelming dominance of the Conservatives in the country, begun with the 1979 victory of Mrs. Thatcher. She later led the Tories to two further victories against Labor, in 1983 and 1987, and demoralized and stripped the party of much of its power and influence.

Mrs. Thatcher is retiring from the House of Commons after 33 years.

That Labor did as well as it did in yesterday's poll is a tribute to Mr. Kinnock, who is 50.

Taking over as head of the party after its ignominious defeat in 1983, he purged it of extremist leftists, reshaped its policies, freed it of domination by union leaders, and generally moved the party closer to the center, making it more acceptable to the mainstream British electorate.

Another outcome the election clearly indicates is something of a turning away by the electorate from the policies of Mrs. Thatcher, modified and carried into the campaign by Mr. Major.

Polls had consistently shown that the principal preoccupations of the British people were the state of the economy and, to a lesser but still significant extent, the condition of the National Health Service, the keystone of the welfare state erected here after the war.

Mrs. Thatcher's drive to privatize virtually every nationalized industryin sight led her and her successors to introduce free market policies into the socialized medical system, which alarmed many people.

Also, residual anger at one of her cardinal policies -- the poll tax, which Mr. Major began dismantling -- gave some impetus to the Labor campaign.

Two recessions have afflicted Britain during the 13 years of Conservative rule, and they have left many victims in their wake.

As Mr. Major said at his last news conference Wednesday, "Recessions hurt people." This was his explanation why the race had been so close. Without the recession, he was certain, the Conservatives would have won easily.

Hurt particularly by the recession were the 200,000 people who lost their homes last year to bank foreclosures and those involved in thousands of business failures.

Unemployment is at a five-year high, over 9 percent. The good news is that inflation stands at only about 4 percent, which the Conservatives insist puts money into people's pockets -- if they have jobs.

In Scotland, where the issue of local self-government or full independence was further inflamed by the election, the Conservatives apparently gained one seat, giving them 10 of the 72 Scottish seats in Parliament. The BBC projected that the Scottish National Party may have lost three or four seats. The SNP had been tipped by the polls to gain two seats.

Throughout the campaign the Conservative Party underwent strong criticism for its lackluster effort, especially from grass-roots party workers.

The Tories planned to beat Labor by portraying them as high taxers, and Neil Kinnock as unfit to be the prime minister. As it turned out, Mr. Kinnock's stature grew during the campaign, Mr. Major's shrank some.

By pounding on the issues of the economy and national health system, Labor was able to keep Mr. Major and the Conservatives on the defensive much of the time.

So how did Mr. Major turn it around?

There is no certain answer to this, but throughout the campaign, the Conservatives had been banking on what was termed here the "cold feet factor." This describes the residual fear they anticipated would come over many Britons when they finally came to vote -- especially older ones who remember the chaos during the last years of Labor governance in the late 1970s.