Correction: The original version of this item said Robert Garagiola did not mention his work for the lobbying firm Greenberg Traurig on his congressional campaign biography. Garagiola recently added that information to his biography after the issue drew media attention.

Another day, another volley of fire in Maryland’s most competitive congressional primary.

In the redrawn seat held by Rep. Roscoe Bartlett (R), the campaign of financier John Delaney is attacking his foe in the Democratic primary, state Sen. Robert Garagiola (Montgomery), for representing a well-known Republican client during his days as a federal lobbyist.

When he was elected to the Senate in 2002, Garagiola was working as a lobbyist on health-care issues for the firm Greenberg Traurig, a fact that he omitted from disclosure forms at the time and does not mention on his Senate biography. (Garagiola added the lobbying tenure to his campaign biography after the issue drew media attention.*) Among Garagiola’s clients, records show, was Berman & Co.

That’s the firm of Rick Berman, whom Democrats and liberal groups have criticized for using corporate-funded groups to attack unions and consumer-safety rules, among other targets. The Delaney campaign alleged that “under Berman’s direction, Garagiola pushed the right-wing healthcare agenda in Washington.”

In response, the Garagiola campaign said “Rob doesn’t recall lobbying for Rick Berman, and he certainly never pushed the right-wing health-care agenda or lobbied against healthcare reform as the Delaney camp falsely accuses him of doing.”

Senate records show that Garagiola was one of three or four Greenberg Traurig lobbyists, depending on the reporting period, working for Berman on the issue of health-care tax credits for the uninsured, a key plank in President George W. Bush’s health-care agenda.

Garagiola campaign manager Sean Rankin said Delaney was trying “to mislead voters about Rob’s time as a junior staff person, where he had no clients of his own, much less advocated on behalf of right wing causes, but Delaney is still hurting badly as a result of his direct choice to write a check for $2,400 to Andy Harris, which he can’t escape, so he keeps trying to pull Rob into the mud with him.”

Garagiola’s team has frequently hit Delaney for his 2010 contribution to Harris, a Republican who ousted Rep. Frank Kratovil (D) in a hard-fought race.

Delaney has not explained his donation to Harris, but his campaign has sought instead to emphasize his hefty donations to Democratic candidates and causes over the years.

Similarly, Garagiola’s staff sidestepped the question about Berman and focused instead on Garagiola’s tenure as an aide to Rep. Frank Pallone (D-N.J.) — before he became a lobbyist — when he worked extensively on children’s health-care issues.

This item has been updated since it was first published.