WASHINGTON — A day after Republican leaders said that their tax overhaul plan would be released in just two weeks, the Republican chairman of the powerful Senate Finance Committee had a different message: not so fast.

Senator Orrin G. Hatch of Utah sought on Thursday to temper anticipation that a fully developed tax plan would be ready for public consumption by the end of the month, insisting that his committee would use a bipartisan process to craft legislation. The remarks, made at the beginning of a hearing about the individual tax code, suggest that the promise to rewrite the tax code by the end of the year may not be attainable.

“Any forthcoming documents may be viewed as guidance or potential signposts for drafting legislation,” Mr. Hatch said.

After the hearing, Mr. Hatch was also muted about the prospects of a tax bill being enacted this year. Noting that it had been more than 30 years since the last big tax bill, he said, “Nobody’s convinced this can get done in a very short period of time.”