LONDON, NOV. 29 -- A visibly nervous John Major, making his first appearance in the House of Commons as Britain's new prime minister, got roughed up verbally today by the opponent who is already gunning for his job, Labor Party leader Neil Kinnock.

Kinnock drew blood during the ritual prime minister's question time when he challenged Major to abolish the "poll tax," the unpopular new system of local government taxation championed by predecessor Margaret Thatcher.

Clearing his voice and faltering several times under a barrage of catcalls from the opposition benches, Major would only concede that "further refinements may be necessary to ensure {the tax} is accepted throughout the country."

It was a shaky start for Major and an important moment for Kinnock, whose party has seen the substantial lead it enjoyed in the polls against the Thatcher-led Conservatives melt away in recent days following her sudden political demise and the emergence of Major as a conciliatory and unifying leader.

A Louis Harris poll today gave the Major-led Conservatives an 11 percentage-point lead over Labor. Just over two weeks ago, with Thatcher in charge, Labor held a 15-point advantage.

Major outpolled Kinnock by 46 percent to 24 percent as best choice for prime minister, and 59 percent of those surveyed believed the Conservatives would win the next general election. But the poll also contained a potential time bomb for the new leader: 60 percent of the 1,092 respondents believed Major should discontinue Thatcher's policies -- a difficult maneuver for a leader who inherits much of his predecessor's supporters.

Labor's leaders are discounting the Conservative surge. Robin Cook, Labor's health spokesman, told reporters: "When the dust settles and the public discovers that they've still got record mortgage rates, a poll tax to pay next year, crumbling schools and hospitals that are closing, then John Major's honeymoon will be very short -- more like a one-night stand."

A senior Conservative Party minister, speaking not for attribution, conceded his party's new lead would fade. But he said the new Labor Party, remade by Kinnock in recent years into a more pragmatic, less socialistic movement, faced a longer-term problem. Having spent the last decade running against Thatcher, Labor now faces the problem of having lost its favorite target and lacking a political philosophy that differs much from that of the Conservatives.

"What they're saying is 'Here chaps, we can manage the market economy better than the Conservative Party,' " he said. "It's not a very convincing philosophical pitch."

Some Labor lawmakers have suggested informally that Kinnock, who has been party leader for seven years, should consider resigning so that the party can present a new face to counter Major. Kinnock has laughed off the idea -- but his assertive performance on the House of Commons floor today appeared designed to quell any talk of a party revolt similar to the one that unseated Thatcher last week after 11 years as prime minister.

Major is known as a lackluster speaker, and his wooden performance this afternoon is unlikely to do him much immediate harm with Conservative lawmakers, who are delighted that their bruising, divisive leadership contest is behind them. But he faced another revolt from women lawmakers furious that his 22-member cabinet does not contain any women.

Tonight his office announced the appointment of Gillian Shephard as a deputy treasury minister, the first woman ever to serve at that level at the treasury. Major told the Commons he eventually would add women to the cabinet, but only "as those women wish it to be . . . on merit."

That did not satisfy some legislators. "A lot of men still only relate to women as nannies, grannies and lovers and not as actual colleagues working side by side with them," complained Teresa Gorman, who noted that, except for a brief interim, every British cabinet since 1964 has included a woman member.

Thatcher, who is still a member of Parliament, attended today's session as a Tory backbencher, taking up the same seat she sat in 31 years ago when she first entered Parliament. She got much applause from her Tory colleagues.

There was less applause for Michael Heseltine, the challenger who toppled her leadership, as he took his new place in the front bench of cabinet members. "Good afternoon, Judas!" yelled one Labor member to the new secretary for environment and local government.