An open clash between Prince George's County and District of Columbia officials over the proposed shift of a major Southeast Washington bussubway transfer station erupted Tuesday.

The Prince George's County Council, at the urging of County Executive Winfield M. Kelly, voted to tell District and Metro officials that the city's refusal to permit passenters to transfer at the Potomac Avenue station is unacceptable to the county.

The letter implied that the county will refuse to support Metro's proposed bus-rail transfer plan unless the city backs down. Metro's two Maryland directors, acting together, have the power to block that plan.

The Potomac Avenue station is half a block from 14th Street and Pennsylvania SE, near the western end of the Sousa Bridge across the Anacostia River. It is on a subway line scheduled to go into service July 1.

District officials have insisted that buses from Anacostia and Prince George's should be diverted to teh Stadium-Armoiry station, located on the same subway line but about two thirds of a mile farther from downtown. They say this would protect the residential area around Potomac Avenue.

In the protest letter, the County Council contended that the shift would add $150,000 a year the county's Metrobus subsidy, increase travel time for commuters up to 12 minutes a day and result in higher fares for the longer rides commuters must take on the trains.