And Brown wants to be seated; there are Senate votes he doesn't want to miss.

Republican Scott Brown is expected to be sworn in Thursday at 5 p.m. after calling on the governor of Massachusetts to immediately certify the results of his upset Senate win, congressional officials told Fox News.

Brown is expected to obtain the necessary signatures from Massachusetts Gov. Deval Patrick and Secretary of State William Galvin.

Patrick spokesman Kyle Sullivan said in a written statement that Patrick will certify the results Thursday morning and "ensure that Senator-elect Brown's request to receive the final paperwork by 11:00 a.m. tomorrow is fulfilled."

The certification will allow Brown to be sworn in earlier than he had originally planned. He said he asked to be seated earlier because there are Senate votes he doesn't want to miss.

That reversed Brown's earlier declaration that he did not want to be sworn in until Feb. 11, a grace period he said he needed to hire a staff and prepare for his new responsibilities. It also followed criticism from conservative radio hosts and newspaper columnists about what one dubbed a "three-week victory lap."

The senator-elect didn't specify which Senate votes in which he may want to participate. Once sworn in, Brown would give the GOP 41 votes in the Senate, one more than the party needs to sustain a filibuster of Democratic initiatives.

In a letter Wednesday to Democratic Gov. Deval Patrick, Brown's attorney, Daniel Winslow, said he wanted the results of the Jan. 19 election certified by 11 a.m. Thursday so they could be forwarded to Senate officials for immediate action. (CONTINUES HERE)