LONDON — There is a growing conviction here that Prime Minister Margaret Thatcher may be permanently damaged by a major scandal that continues to haunt her.
Veteran observers across the breadth of British politics are now convinced the damage will last for awhile and inhibit her leadership. If she is unable to squelch the lingering doubts about her personal role in the unseemly scandal, that damage could be permanent and irreparable.
Even members of Parliament from within her own Conservative Party who recently rallied to Thatcher with an important vote of support in the House of Commons now talk of the scandal as a watershed in her prime ministership and a political blow from which she will never recover.
The scandal began in apparently harmless differences within her Cabinet last November over the future of a financially troubled defense contractor, the Westland company, a helicopter maker. But it quickly mushroomed into an embarrassing confrontation that led directly to the resignation of two senior Cabinet ministers and has cast doubt about Thatcher's competence and credibility.
While there appears to be no immediate threat to her position as prime minister, if events should go badly for her in the coming months, pressure would almost certainly mount among leading Conservatives for her to step aside as party leader, a possibility virtually unthinkable two months ago.
This sudden erosion of power for a leader many consider one of the most dominant, determined British prime ministers in this century carries widespread implications.
Thatcher, who has dominated her Cabinet and her party, and has changed the terms of political debate in the country through determination and the force of her personality, has suddenly been placed on the defensive. She will now be forced to be more cautious, to move more slowly and to consult more thoroughly, according to those assessing the effects of the affair.
Party colleagues, who had come to respect her political instincts and believed that if all else failed, she would win through pure force of will, now privately question those instincts, and the results of her perseverance.
One Conservative member of Parliament has called for Thatcher to step down as party leader before the next election.
"The time has come when we should be thinking in terms of choosing another leader," said Antony Meyer, who has criticized Thatcher's policies on previous occasions.
More disturbing for Thatcher is a mounting disquiet among members of Parliament loyal to her. Thirty Conservative MPs voted against her recommendation on a monetary matter in Parliament on Feb. 3, and the following day she was assailed from both parties while answering parliamentary questions on matters unrelated to the scandal.
Then, on Feb. 6 she was forced to abandon a plan to sell state-owned Austin Rover auto production facilities to Ford Motor Co. as part of her denationalization program. Heavy opposition had developed in the Cabinet and among other Conservative members of Parliament.
Her public image as a trusted, no-nonsense leader has also suffered.
A nationwide Harris poll conducted last week indicated that 56% of the British public did not believe her statements about the Westland affair. A British Broadcasting Corp. survey of 500 viewers the morning after her statement found only 20% felt she had told "the whole truth."
"The balance of power in the medium and even the long term has shifted against her," said Anthony King, professor of government at Essex University and a respected political commentator.
Less clear is the impact the scandal will have on her international stature, which has grown steadily with her domestic successes. She is one of the longest serving heads of government in the Western alliance and the European leader considered to be closest to President Reagan.
Much of Thatcher's problems centers on the involvement of her office in the surreptitious disclosure of a highly sensitive, confidential letter connected to the affair.
The letter, from the country's second-ranking law officer, Patrick Mayhew, to then-Defense Secretary Michael Heseltine, accused Heseltine of misrepresenting the facts in presenting his point of view in the dispute.
Heseltine and Trade and Industry Secretary Leon Brittan subsequently resigned over the issue, and two of Thatcher's closest aides were linked with the decision to leak the letter. The prime minister's opponents contend that Thatcher and Brittan agreed to leak the letter, hoping it would discredit Heseltine, her opponent in the unseemly Cabinet dispute over whether an American or a European firm should bail out financially troubled Westland.
Westland shareholders Wednesday chose the American firm, Sikorsky.
Disclosing the existence, let alone the contents, of a letter from such a senior law officer to a Cabinet minister without the author's permission is a major breach of government procedure.