Senate Parliamentarian Robert Dove, the official responsible for enforcing the chamber's rules and procedures, has been asked to leave his post after a dispute with the Republican leadership, Senate sources said yesterday.

Dove angered Republicans, especially Majority Leader Trent Lott (R-Miss.), with at least two recent rulings that effectively made it harder for the GOP to push President Bush's budget and tax cut proposals through the evenly divided body.

Republicans declined to say why Dove had been asked to leave, but his departure will force the appointment of a new parliamentarian -- one of the Senate's most important, if least-known, officers at a time in which the Democrats and Republicans are seeking to operate under an unprecedented power-sharing arrangement.

The office of the parliamentarian has always been one of the most important in the Senate, but Dove's rulings have been particularly sensitive this year with the body split between 50 Democrats and 50 Republicans. The controversy that led to his dismissal underscores the degree of frustration felt by GOP leaders as they seek to advance the agenda of the first Republican president in eight years.

There were conflicting reports about whether Dove was fired, rehired and then told he had to go, or was simply "given notice," as one source put it, that he would have to leave. But a senior Republican aide confirmed that Dove had been dismissed by Secretary of the Senate Gary Sisco Thursday at Lott's behest and would probably continue to work for no more than a month.

Dove, 62, an employee of the Senate since the mid-1960s, was at his desk on the Senate floor yesterday but did not return a phone call to his office. Sisco, who is Dove's immediate boss, issued a terse statement describing the situation as an "internal matter" and declining further comment. Lott told reporters he wanted to talk further with Dove before saying anything.

The parliamentarian serves at the will of the Senate secretary, who is chosen by the majority leader, and advises the presiding officer on rules, procedures and precedents -- a job requiring a high degree of expertise and experience. The presiding officer, who is often a junior member of the Senate, nearly always takes the parliamentarian's advice.

Democrats often complained privately that Dove tilted toward the Republicans, but, especially since the 50-50 Senate was elected last fall, his rulings have come under fire from Republicans as well.

The GOP's unhappiness came to a head during the tax and budget debate. Typically, Senate bills can be filibustered -- a parliamentary stalling tactic -- until supporters can assemble 60 votes. But Senate rules allow passage of certain budget measures by a simple majority, and Republicans want to apply those rules to a series of tax votes.

Several Republican sources said Dove angered GOP leaders when he said the Senate could use the provision for only one tax-reduction measure. Because of Dove's decision, the GOP may need 60 votes to break a filibuster for these tax bills -- a much more difficult hurdle since Democrats hold 50 seats -- or strike a deal with the opposite party.

Democrats were upset because they contended that none of the tax cut bills should have been protected from filibusters by rules designed to reduce budget deficits.

The "final straw," as one GOP aide described it, came late last week when Dove told Republican leaders that they would have to produce a 60-vote majority for the 2002 budget if it included a $5 billion fund to cover damage from natural disasters. The rules do not provide for such a fund, triggering the requirement for 60 votes. Republicans are having trouble getting even 50 votes for the budget, which is scheduled for a vote later this week. As a result, the GOP dropped the provision.

Reports of the dispute and Dove's dismissal were first reported in Roll Call, a Capitol Hill newspaper.

Dove served as parliamentarian after Republicans took control of the Senate in 1981. He was dismissed by the Democrats when they regained control in 1987 and became a consultant in the office of then-Republican leader Robert J. Dole (Kan.). When the GOP took back the Senate in 1995, Dove again became parliamentarian, although his relations with Lott have never been described as particularly close.

The power-sharing arrangement that was negotiated last winter between Lott and Senate Democratic leader Thomas A. Daschle (S.D.) did not cover Dove's position.