HARRISBURG -- A Democratic lawmaker is telling colleagues he will support Republican John Perzel for speaker of the state House of Representatives, a move that would foil the Democrats' chance to assume the leadership post.

In a letter dated today, Rep. Thomas R. Caltagirone of Berks County wrote that he will cross party lines to help keep the speaker's gavel in Perzel's hands.

"I have always found Rep. Perzel to be a man of his word, and serious about the issues of public policy," Mr. Caltagirone wrote. "I believe the people of Pennsylvania will be best served if he is elected as speaker on Jan. 2, and he will have my support."

The speaker sets the House's voting agenda and moves bills into committees, making it the most powerful job in the chamber.

The November election gave Democrats a 102-101 majority in the House, theoretically giving them the power to elect their own speaker and majority leader when they convene Tuesday.

But Mr. Perzel, R-Philadelphia, has resisted pressure from Democratic leader Rep. Bill DeWeese of Greene County to relinquish his Capitol offices, fueling speculation that he would try to retain the speakership through a Democratic defection or some other means. Republicans have held the post for 12 years.

Mr. Caltagirone's letter, first reported in the Reading Eagle on Saturday, said he planned to remain a Democrat.

"I have become increasingly distressed over the years with the manner in which our Democratic leaders have conducted the business of the caucus," he wrote. "The leaders of our caucus have shown little regard for many members of the caucus, the constituents they represent, and the legislative initiatives we should be supporting."

Messages seeking comment from Mr. Caltagirone, Mr. Perzel and Mr. DeWeese were not immediately returned.