Baltimore County Executive Kevin Kamenetz. (Evelyn Hockstein)

A top Baltimore County government official has urged his staff's "full participation" on Monday in a "very important announcement" by County Executive Kevin Kamenetz (D), who is expected to launch a run for governor this week.

"We have been invited to join County Executive Kamenetz on Monday, September 18th at 11:15 am as he has a very important announcement to make," says the email from county IT chief Robert R. Stradling to employees of his agency. "I am encouraging full participation to support our County Executive as he makes this very important announcement."

The email could violate state ethics rules that prohibit officials from using government time and resources to support political activity or using their positions to benefit individuals involved in political campaigns.

In response to questions about the message, Stradling said he had heard that Kamenetz would be making a major announcement and wanted to encourage his staff to attend.

On Sunday, he sent another email to employees that said: "To clarify my email regarding Monday's announcement by the County Executive, if you choose to attend, you will need to use your personal leave time or attend on your lunch hour."

Sean Naron, a spokesman for Kamenetz' political operation, said the county executive "will be making an announcement about his future Monday." He declined to provide further details.

County spokeswoman Stacie Burgess said before Kamenetz's announcement that it would not be government-related.

"An employee appears to have gotten overly exuberant. No more, no less," Burgess said.

Baltimore County Democratic Party chair Tara Ebersole said she had expected Kamenetz to announce this week that he is running for governor.

Kamenetz, a lifelong Baltimore County resident, is finishing his second term as executive, after 16 years on the County Council — including four as its chairman. He was a member of the Democratic State Central Committee for 12 years and serves as president of the Maryland Association of Counties.

He would join a crowded field of Democrats vying to challenge Hogan in the 2018 election, including Prince George's County Executive Rushern L. Baker III, former NAACP president Ben Jealous, state Sen. Richard S. Madaleno Jr. (Montgomery), entrepreneur Alec Ross, Baltimore lawyer and former University System of Maryland Board of Regents chair James L. Shea, and Krishanti Vignarajah, a onetime policy director for former first lady Michelle Obama.