ROMULUS, MICH., DEC. 10 -- Rep. Jack F. Kemp (R-N.Y.) and Marion G. (Pat) Robertson today struggled to hold their conservative coalition together as the battle for this state's 77 GOP delegates turned into a nasty brawl.

"I hate to say they {supporters of Vice President Bush} are trying to steal one, but that's what's happening. I'm going to put principle above politics, and I think Jack Kemp is doing the same thing," Robertson said as he and Kemp toured Eastern Michigan in a last minute drive to shore up support for a key vote of the Republican Central Committee on Saturday.

"If Jack Kemp and Pat Robertson are going to put the principle of theft above politics, that is their prerogative," said Rich Bond, Bush's deputy campaign manager. "It is absolutely incredible that Jack Kemp would put the potential success of his own candidacy down the tubes to help Pat Robertson defeat George Bush."

The harsh exchanges, which include charges by dissident Kemp supporters that Robertson is a liar, grow out of an explosive fight over proposed changes in the rules that govern how Michigan will become the first state to select national convention delegates.

Up until four days ago, Robertson appeared to have a near lock on winning at least a plurality of the Michigan delegation to the GOP National Convention in New Orleans. He and Kemp had joined forces to gain control of a majority of 9,000 "precinct delegates" elected in the 1986 Michigan primary. Those delegates will pick the 77 national delegates first through county conventions on Jan. 14 and then at a state convention Jan. 29-30.

The deal, however, began to collapse on Monday when two out of three of Kemp's Michigan cochairmen suddenly announced that they had independently worked out a separate deal with Bush, under which Bush would win a plurality and Kemp would get second place, with Robertson falling in last place.

A key step in the battle is the Saturday meeting of the central committee, when the 101 members will decide whether to adopt rules favoring Robertson or rules favoring Bush. That vote, because of the Kemp defections, is considered to be very close, although the Robertson-Kemp alliance appears to have a slight edge at the moment.

While the Kemp defectors contended that Kemp would come out with more delegates in the deal with Bush than in the deal with Robertson, Kemp's Michigan manager, Dick Minard, said it is more important to defeat Bush in Michigan than to win more delegates.

"The front-runner {needs} to be defeated or slowed down," he said.

Kemp spent the day not only trying to persuade his supporters on the central committee to hold firm, but to rebuild his own campaign, which was hurt by the defection of state Sen. Richard Posthumus, state GOP Vice Chairman Larrain Thomas and two key GOP activists, Saul and Andy Anuzis.

Kemp announced seven new cochairmen for his campaign, which has been running into trouble not only in Michigan but also in what was to be a key state for him, New Hampshire. The campaign is also in financial trouble.

Charles Black, Kemp's national campaign manager, acknowledged that more money has been borrowed beyond the $1.95 million borrowed in anticipation of federal matching grants. "We did go to the bank," Black said, but he declined to provide details. In another setback, the latest CNN poll in New Hampshire placed Kemp last among the six GOP candidates, with just 2 percent of the vote. Three months ago, the same poll found him in third place.

The Kemp defectors here contend they are still supporting the New York congressman, but argue that Robertson has had all the benefit of the Kemp-Robertson coalition, while treating Kemp in a demeaning and insulting fashion.

Andy Anuzis, in a letter to Robertson supporters, quoted Robertson as saying Kemp had indicated a willingness to accept the vice presidency. "This is a lie . . . , " Anuzis wrote.