Accusing the head of the Prince George's County Public Works and Transportation Department of failing to follow new cost-cutting measures, County Executive Lawrence J. Hogan demanded yesterday that the official retire immediately instead of on Jan. 27.

Donald Dhnker, 53, has headed the department since 1974, when he was appointed by then-executive William W. Gullett, and had worked in the public works department since 1951.

Yesterday, Hogan released a threepage statement announcing that Dunker's retirement had been made effective immediately and listing three instances in which Dunker allegedly failed to follow Hogan's costcutting directives.

Most recently, the statement said, Dunker gave Hogan a memo on Monday listing expenses of $11,000 for snow removal last weekend and $4,600 in overtime payments for the snow removal, refuse collection and operation of the county landfill, despite Hogan's order that all proposals for overtime be submitted to him in advance.

Moreover, the statement asserted, "a public works employe was observed on two separate days, Jan. 6 and 7, on a county roads project at D'Arcy Road watching television... during working hours."

Dunker said last night that Hogan had asked for his retirement Monday evening. He refused to comment on the executive's accusations.

Dunker said he had approached former county executive Winfield M. Kelly Jr. about retiring last summer, but that Kelly had persuaded him to remain in his job through the end of the year. Dunker had announced his retirement as of Jan. 27.

Hogan also accused Dunker of failing "to make the most efficient use of his crews," and of authorizing 40 county cars for take-home use by his employes despite Hogan's recent order that employes be denied the privilege of taking cars home. According to Hogan's statement, Dunker authorized employes to take the cars home from December through March in case a snow removal operation was necessary.

Hogan announced his cost-cutting measures Dec. 7.

Hogan's statement also accused Dunker of failing to respond to Hogan's request Dec. 28 that public works employes establish a 30-mile-an-hour speed limit along a section of road in south Prince George's County in response to senior citizens' complaints.

Yesterday, Paul Staubus, who was named to replace Dunker temporarily, was unsure how Dunker's alleged abuses would be corrected. "We're waiting for some direction from Mr. Hogan and we're trying to get together some information for him on snow removal."