Last month, Michael Grimm's campaign aides tried to take away one of Rep. Dan Donovan's ballot lines.

But they got creative. A Grimm campaign operative filed an extra petition with the city's Board of Elections for Donovan for the Reform Party Line. He did it just before midnight on the day of the deadline.

That extra petition triggered an arcane rule at the Board of Elections: the entire filing would need a cover sheet, which the Donovan team never filed.

It was an attempt to invalidate the entire filing and take the line away from Donovan.

"My understanding is after this ruling comes down, the Reform Party is going to refer this case to the United States Attorney's office," said Donovan, who is running against Grimm in the Republican primary. "They believe a federal crime may have occurred, and we'll see what the result of that investigation is."

"This is outrageous, it's shameful, and I hope the commissioners will send a powerful message to anyone that tries to defraud the election process like this," said Frank Morano of the Staten Island Reform Party.

At the Board of Elections on Tuesday, the board rejected the Grimm campaign's move, letting Donovan keep the line.

It also went a step further: It will indeed refer the issue to local prosecutors, including the U.S. Attorney's office.

Grimm did not want to go on camera for this story, but his campaign was alleging Donovan was also up to dirty tricks.

A campaign spokesman sent us grainy security images, claiming representatives from the Donovan campaign were going door to door, claiming they were Board of Elections investigators, looking into Grimm's petitions for the Conservative Party.

The Grimm campaign said it filed a police report, alleging these people were wrongfully impersonating government officials.

Donovan denied his campaign did any such thing. "We were investigating whether or not his signatures were correct," said the congressman, who represents Staten Island and a portion of Brooklyn. "There were people that were checking to make sure they were correct, but nobody harassed anyone."

These third party ballot lines are often coveted because they will be helpful come November, when one of these Republicans faces off against a Democrat in the general election.