Outside spending from national political parties and PACs on the U.S. Senate race has hit $10 million — with the money split about evenly between backers of Democrat Richard Carmona and Republican Jeff Flake.

The latest big investment came this week from the American Federation of State, County and Municipal Employees, which paid $1.2 million for a TV ad attacking Flake. The 30-second spot says Flake’s “extreme, right wing ideas don’t belong in Arizona.”

Groups supporting Carmona have spent $5.1 million while organizations backing Flake have spent $4.9 million. This includes money spent to air TV ads, send mailers, pay for polling and provide staffing, FEC data shows.

The money has fueled a flurry of attack-style TV ads.

One of the newest TV ads is from the National Republican Senatorial Committee hammering Carmona on what they deem his inability to work well with others and pattern of "bullying co-workers."

Most of the money, $6.6 million, has been spent since Oct. 8 — the week that early ballots went out to voters.

Here are the six groups that have spent the most:

• National Republican Senatorial Committee (backing Flake) — $1.9 million

• Democratic Senatorial Campaign Committee (backing Carmona) — $1.79 million

• Club for Growth PAC (backing Flake) — $1.57 million

• American Federation of State, County and Municipal Employees (backing Carmona) — $1.2 million

• Majority PAC (backing Carmona) — $1.1 million

• Freedomworks for America PAC (backing Flake) — $897,600

Stay tuned to the Pueblo Politics blog throughout 2012 for news, updates and information about Arizona politics. You can follow Arizona Daily Star reporters Brady McCombs, Becky Pallack and Tim Steller on Twitter.