WASHINGTON (AP) -- Democratic U.S. Senate candidate Jim Slattery is releasing his first television ads this week, as he tries to compete against the better-funded campaign of incumbent Republican Sen. Pat Roberts.

The former congressman from Topeka will air two 30-second spots starting Tuesday in TV markets across the state, including Kansas City, Topeka, Wichita, campaign spokeswoman Abbie Hodgman said Monday.

Both ads play on a well-worn theme for Slattery's campaign -- that Roberts has been in Washington too long.

The first ad shows images of the Apollo rocket launch that led to astronauts walking on the moon.

"Nearly 40 years ago, Neil Armstrong walked on the moon," Slattery says. "And Pat Roberts was already in Washington."

"The world has changed a lot since then and it's time for new leadership," Slattery says, standing in a corn field on his family's farm in Atchison County.

In a second ad, targeted at younger voters, Slattery again reminds voters how long Roberts has worked in the nation's capitol. Slattery says there's a need for change to address new problems like the wars in Iraq and Afghanistan, gas prices, jobs and a growing national debt.

Roberts launched his first TV ad a month ago, taking advantage of a major edge in fundraising, and has been airing a negative TV ad targeting Slattery for more than a week. Though Roberts' seat generally is considered safe, Slattery would be the most formidable opponent Roberts has faced in years.

Roberts campaign spokeswoman Molly Haase said Roberts "never stops working for Kansas," and she criticized Slattery for becoming a lobbyist after leaving Congress in 1994.

"A lobbyist running on change is laughable," Haase said.

Roberts, 72, became administrative assistant to former Rep. Keith Sebelius, R-Kan., in 1969. He was elected to the U.S. House in 1980, representing the 1st Congressional District in Western Kansas after Sebelius retired.

Roberts was first elected to the U.S. Senate in 1996 and is seeking his third term this fall.

Slattery, 59, faces Lee Jones, an Overland Park railroad engineer and former union leader, in the Aug. 5 Democratic primary. But the Democratic establishment is squarely behind Slattery and he is expected to win the nomination.

Slattery raised $646,000 over the past three and a half months and has $638,000 cash on hand, according to his latest fundraising report to be filed with the Federal Election Commission this week.

Roberts raised $972,000 over the same period and has $2.86 million in the bank, according to a report filed with the FEC on Monday. He has spent more than $1 million on TV ads and other campaign expenses.