Philadelphia City Councilmember Kenyatta Johnson and his wife have urged a judge to toss the federal bribery case against them, arguing that prosecutors failed to allege that they explicitly struck a deal with leaders of a South Philadelphia nonprofit accused of paying them off.

The push, outlined in a new filing this week, comes amid the couple’s efforts to fend off the allegations against them before they are due to stand trial next year — and it offers the first glimpse of what their defense might look like once the case is presented to a jury.

Federal prosecutors in January charged Johnson, 46, and his wife, Dawn Chavous, 40, with accepting more than $66,750 between 2013 and 2014 from two executives at Universal Companies, a community development charity and charter-school operator founded by music producer Kenny Gamble.

Hiding the bribes in the form of a consulting contract to Chavous, prosecutors say, the executives — former CEO Abdur Rahim Islam and ex-CFO Shahied Dawan — bought the councilmember’s protection when disputes over properties it owned came before Council or other city boards.

But in court filings Monday, Johnson and Chavous' attorneys argued that the government had offered no evidence that any of the parties had agreed that Chavous' contract with Universal had anything to do with Johnson’s votes on matters involving Universal’s landholdings.

“Put simply, there is no … evidence that Universal retained Chavous Consulting in order to bribe Councilmember Johnson,” defense lawyers Patrick Egan and Barry Gross wrote.

» READ MORE: Inside the FBI investigation into Philly Councilman Kenyatta Johnson, his wife, and Kenny Gamble’s nonprofit

Chavous’ lawyers argue that she was eminently qualified for her job at Universal as a leading education consultant, campaign adviser, and advocate for charter schools. She has described as insulting the accusation the contract was given to her as an under-the-table payoff to her husband.

Prosecutors maintain she did next to no work over the 14-month life of the contract and around that same period Johnson made several consequential decisions regarding Universal’s landholdings in his district, which covers South and Southwest Philadelphia.

That included securing a rezoning ordinance in 2014 for the Universal-owned site of the former Royal Theater on South Street. The nonprofit had struggled unsuccessfully for years to redevelop the site after purchasing it for $286,252 in 2000. Efforts to sell it also failed, due to potential buyers' doubts about the economic viability of developing the property under its zoning restrictions.

With Johnson’s assistance, the site was rezoned for mixed-use development featuring apartments and retail space — a move Johnson’s lawyers described in court papers Monday as “nothing more than an expression of his legitimate position regarding development within his district” and one that, they noted, came shortly after Universal’s contract with his wife had ended.

The nonprofit then sold the property within a year for $3.7 million — nearly 13 times what it originally paid.

Prosecutors have also accused Islam and Dawan of paying off Johnson and Chavous when Universal was in danger of losing ownership of a parcel of properties it had bought from the city at a cut-rate price of $3 at 13th and Bainbridge Streets in a 2005 deal that required the nonprofit to build 109 single-family homes on the site within 18 months.

The land remained undeveloped eight years later, prompting the Philadelphia Redevelopment Authority to take steps to rescind the nonprofit’s ownership.

But Johnson told the authority he would not support taking the land back from Universal — an influential position given Council’s long-standing practice of deferring to the wishes of councilmembers regarding development issues in their districts.

Johnson’s lawyers maintained Monday that his approval wasn’t legally required for the PRA to move forward and balked at the idea that his refusal to support a government effort that never got off the ground could be considered an official action under federal bribery statutes.

“Declining to take an official action is not an official action,” they wrote.Prosecutors are expected to respond to those arguments in the coming weeks.

Islam and Dawan also face charges of tax evasion stemming from more than $500,000 they allegedly embezzled from Universal and in a separate alleged bribery scheme involving the former school board president in Milwaukee, where Universal operated two charter campuses.