Three Republican candidates are seeking their party’s nomination for the U.S. Senate, but only two of the five congressional seats will be contested Monday at the state Republican convention.

The Republicans seeking the nomination to challenge U.S. Sen. Richard Blumenthal are state Rep. Dan Carter, Jack Orchulli, and August Wolf. Orchulli ran against U.S. Sen. Chris Dodd in 2004 and ran for state Comptroller in 2010, but lost to Kevin Lembo. Wolf has never sought public office.

Carter, 48, is in his third term in the General Assembly and said he knows how to build a campaign team and fundraise.

The last Republican to represent Connecticut in the U.S. Senate was Lowell Weicker, who was elected in 1970 and defeated in 1988 by Joe Lieberman. The last Republican to hold a Congressional seat in Connecticut was Chris Shays, who was defeated in 2008 by U.S. Rep. Jim Himes.

As of Sunday, it looked as if Matthew Corey, who owns an Irish bar in Hartford, is the only Republican lined up to run against U.S. Rep. John B. Larson in the 1st Congressional District. Corey challenged Larson in 2014 and lost by more than 57,000 votes. Angel Cadena Jr. is the only Republican looking to challenge U.S. Rep. Rosa DeLauro in the 3rd, and state Rep. John Shaban, a three-term state representative from Redding, is the only one seeking to challenge Himes in the 4th.

But in the Second District it looks as if Daria Novak, who will make her third attempt to defeat U.S. Rep. Joe Courtney, will face a challenge from Westbrook tax attorney Ann Brookes. Novak received the Republican Party’s support at the 2010 convention, but lost the primary to former news anchor Janet Peckinpaugh. In 2012 she failed to win enough support at the Republican convention. That year, state Sen. Paul Formica of East Lyme challenged Courtney and lost.

In 2014, Lori Hopkins-Cavanagh, a real estate agent and failed New London mayoral candidate, lost her challenge by more than 61,000 votes. The last Republican to hold the seat was former U.S. Rep. Rob Simmons, who Courtney defeated by less than 100 votes in 2006.

In the 5th Congressional District, Sherman First Selectman Clay Cope is facing Newtown businessman Bill Stevens. Matt Maxwell dropped out of the race and endorsed Cope on May 5. John Pistone, who has run as a petitioning candidate when he didn’t get the Republican nomination in the past, has filed paperwork for another run this year. In 2014, Pistone received just 1,970 votes.

Last year, Mark Greenberg, a three-time candidate for the 5th Congressional District, came within striking distance of U.S. Rep. Elizabeth Esty, but ended up losing by more than 15,000 votes. In 2012, when it was an open seat because Chris Murphy decided to run for U.S. Senate, Republicans had what many believe their best shot at wrestling at least one seat away from the all-Democratic congressional delegation. That year, former state Sen. Andrew Roraback of Goshen lost to Esty by about 7,461 votes.

The Republican convention will be held at the Connecticut Convention Center in Hartford. The event begins at 5 p.m.