Here’s how to watch the House speaker vote.

As the House of Representatives convenes for the first day of the 118th Congress on Tuesday, Representative Kevin McCarthy of California faces a critical challenge in his bid to become speaker of the House.

Despite Mr. McCarthy’s efforts in recent days to lock up enough support from fellow Republicans to prevail when members elect a speaker, a small group of hard-right lawmakers continued to say on Monday that they would not support him.

While Republicans won control of the chamber in November, the shape of the new Congress will probably come down to how those lawmakers decide to proceed. If Mr. McCarthy fails in an initial vote, Republicans may be forced to hastily move on to a different nominee, and several people who have not previously been viewed as contenders could suddenly be considered serious candidates.

The Times will provide live video at nytimes.com, accompanied by analysis from reporters, beginning at 12 p.m. Eastern time on Tuesday. The vote will also be carried live on C-SPAN and PBS.