Former Alabama state Sen. Lowell Barron

FORT PAYNE, Ala. - Prosecutors in the trial of former state senator and a campaign aide can present evidence that their relationship was more than professional, but they can't discuss whether it was romantic, a judge ruled Thursday.

Defense attorneys for Sen. Lowell Barron, a Democrat from Fyffe, insist Barron and Jill Johnson always had a professional relationship and sought to block testimony about whether it was anything other than that. Prosecutors filed court papers saying the relationship was personal and that the nature of the relationship is relevant to show motive.

"The court agrees that evidence that Barron and Johnson had more than a business-like or professional relationship is relevant, but finds that the probative value of evidence of a romantic relationship would be outweighed by the danger of unfair prejudice," the judge wrote.

Barron and Johnson are scheduled to go on trial Monday on ethics and campaign finance charges accusing them of misusing $58,000 in campaign donations from Barron's unsuccessful 2010 re-election campaign.

Prosecutors from the state attorney general's office also want to use as evidence the statements Johnson made to an investigator and to a grand jury, but the judge said Thursday he is reserving a ruling on that. He did rule that prosecutors can use statements Johnson made to her daughter, Misty Farmer.

Barron, 71, served in the state Senate for 28 years before losing in 2010, when Republicans took control of the Legislature after 136 years of Democratic dominance. Johnson, 48, of Scottsboro served on Barron's Senate staff before switching to his campaign staff for the 2010 election.