Hailed as the end of an era that transformed Britain, Prime Minister Margaret Thatcher's decision to resign has angered supporters, pleased opponents and left three men battling to succeed her.

A new poll Friday indicates the Conservative Party, led by Thatcher for 15 years, stands a better chance of winning an election now that she has agreed to step down when the party picks her replacement next week.Here is a look at the three seeking to succeed Thatcher as party chief - and thus the nation's leader:

MICHAEL HESELTINE

Heseltine, a former defense secretary, calls himself a Thatcherite. But if his leadership bid succeeds, his government would likely be as different in style and content from Thatcher's as it's possible to be in the Conservative Party.

Heseltine, 57, announced his leadership challenge on Nov. 14 and took a giant step toward becoming prime minister on Tuesday, forcing Thatcher into a second ballot for the party leadership.

To a large extent, his appeal to his fellow legislators was that he was not Thatcher: that he would govern by Cabinet consensus, and that he could help them win re-election by modifying her unpopular new per capita community charge, commonly known as the poll tax, and because of his high standing in public opinion polls.

One of the major themes has been his ideal of "caring capitalism," which he has contrasted with the rigorous free-market approach of the Thatcher years.

"I find it difficult to reconcile with what I understand to be the core of Tory philosophy that there are people sleeping in the doorways of so many central London streets," Heseltine said recently.

Although as a Conservative and a self-made millionaire Heseltine favors a market economy, he believes in a closer relationship between government and business.

Heseltine has said he would continue Thatcher's tough policy on the Persian Gulf.

He and his wife, Anne, have three children.

DOUGLAS HURD

Hurd, the foreign secretary, has won respect for his calm handling of a crisis in the Persian Gulf and another crisis in the government.

Hurd, 60, who had supported Thatcher's campaign to stay in power, entered the race to succeed her as soon as she dropped out.

"I believe I can unite the party . . . and that's why I'm putting my name forward," Hurd said Thursday.

The silver-haired former diplomat was Northern Ireland secretary from 1984 to 1985 and home secretary from 1985 to 1989, in charge of law and order and immigration services.

Thatcher appointed him foreign secretary in October 1989 - fulfillment of an ambition Hurd had cherished through a long political career.

Forthright, steely and calm, he played a central role in Britain's involvement in the Persian Gulf.

Hurd, who is fluent in Mandarin Chinese, began his working life as a diplomat, then turned to mystery writing and politics.

The son and grandson of Conservative members of Parliament, Hurd was educated at Eton and Cambridge, where he received a first-class honors degree in history.

Hurd and his second wife, Judith, his former secretary whom he married after a 1982 divorce, have two small children. He has three adult sons by his first marriage.

JOHN MAJOR

Major, at 47 the youngest member of the Thatcher government, won two top Cabinet posts within a decade of entering politics.

The chancellor of the exchequer, or treasury secretary, is seen as one of Prime Minister Margaret Thatcher's personal choices as eventual heir.

A high school dropout and son of a circus performer, Major is the self-made man who symbolizes the changes in the Conservative Party that once was the bastion of Oxford and Cambridge-educated privilege.

A onetime laborer, he is the only Cabinet member to have been on "the dole," or welfare, for eight months. He has lived in suburban comfort and in the tough south London neighborhood of Brixton, where the family moved when one of his father's business ventures failed.

Major's fortunes improved when he joined the Standard Chartered Bank, where he was an executive for 14 years.

He was elected to Parliament in 1979 and in 1981 began a remarkable climb to the top through eight government jobs in as many years.

After the June 1987 general election, Major was appointed chief secretary to the treasury, winning respect for his financial acumen and developing a reputation for quickly grasping figures and detail.

Thatcher chose Major as foreign secretary in July 1989, and he became the top treasury official four months later.

His year has been a rough one for the British economy, with rising inflation, high interest rates and growing trade imbalance - all problems that existed before he took over.

Tall, bespectacled and gray-haired, Major has a calm, modest manner that some call dull and others find engaging. He and his wife, Norma, have been married for 20 years and have a son and a daughter.

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(Additional information)

How Britain will get a new leader

Margaret Thatcher will remain prime minister of the United Kingdon of Great Britain and Northern Ireland until the governing Conservative Party chooses a new leader next week. Here's a look at how the leadership change will work:

Selecting a Prime Minister: Citizens of the United Kingdom do not vote for the prime minister, who is the head of government. They vote for a local member of Parliament. The leader of the party with a majority in the 650-seat House of Commons is the prime minister.

Rules of Election: Each party has its own rules for electing a leader. The Conservative Paarty, which has a 98-seat majority in the Commons, will choose its new leader by a secret ballot on Tuesday. If no candidate wins a majority, there will be a final ballot on Thursday.

Handing over power: When the Conservative Party chooses a new leader, Thatcher will submit her resignation to Queen Elizabeth II. The party's new leader would meet the monarch soon afterward to be confirmed as prime minister, probably within an hour.

Terms of office: Parties are elected to govern for a maximum of five years, but a British prime minister can call a general election at any time. The present government's term runs out in mid-1992.