Even before Seth Williams became district attorney, his advisers worried that his frequent use of campaign funds for what appeared to be personal expenses might one day land him in trouble.

Questionable spending on haircuts and hotel stays and sloppy accounting in the use of his mother's American Express card prompted his then-finance director Aubrey Montgomery to confiscate Williams' campaign debit card in 2008. Nearly a year later, she urged other staffers to keep a close watch on his political committee's coffers.

"The candidate should have very limited access to campaign funds," she wrote in a June 2009 memo. "Disbursements to the candidate should … be vetted before submission."

Now, prosecutors are seeking to use that memo, Montgomery's testimony, and other exhibits from Williams' past against him at his trial next month on federal bribery and campaign finance fraud charges.

Outlining their intentions in recent court filings, they painted the embattled district attorney as a hypocrite who, despite previous warnings, continued to commit – and in some cases zealously prosecuted others for – the same crimes that now threaten to send him to prison.

"His wrongful conduct was motivated – as was all of the charged conduct in this case – by his perpetual inability to live within his means and his desire to enhance his income," prosecutor Robert A. Zauzmer wrote in a court filing Friday.

For instance, even while allegedly accepting gifts worth thousands of dollars from wealthy businessmen, Williams rolled out a splashy media campaign in 2014 to excoriate six elected officials whom his office had charged with accepting a lobbyist's bribes.

"They don't deserve elected officials who think it's OK to sell their office," he said at a news conference. "There are no free passes when it comes to corruption and elected officials who break the law." Prosecutors now hope to share that statement with jurors.

Williams, 50, has denied allegations that he accepted bribes. And his lawyer has pushed to dismiss other charges involving his alleged misuse of political donations at the exclusive Union League and the Sporting Club at the Bellevue.

When Williams' use of those funds was questioned in the past, he portrayed himself as a humble public servant, forced only by the demands of politics to rub elbows with the city's moneyed class at such elite venues.

His own tastes, he told the city Ethics Board during a 2009 investigation of campaign expenses, ran more down-market.

"I don't go to Delmonico's on my own to eat. I don't go to Four Seasons. I don't go to the Palm – for the most part," he said, according to a deposition excerpt that prosecutors hope to use at his trial. "On my own, I would normally just go to, like, Taco Bell."

For her part, Montgomery, his former finance director, told federal authorities that Williams frequently bucked her advice on appropriate use of political donations, including after a trip to the 2008 Democratic National Convention in Denver, expensing to his campaign in-room movies and meals.

"When [she] confronted Williams about these 'add-ons,' Williams stated his belief that he was entitled to a 'per diem' while traveling," Zauzmer wrote in a motion filed last week.

Later, Montgomery said, she used her personal credit card to book Williams' hotel room for the 2009 Pennsylvania Society, an annual gathering of political elites in New York City.

Although she expected that he would use his own card to check into the room, he charged his entire stay – including about $200 worth of in-room movies and room service – to hers and refused to repay her, she said. He allegedly suggested that she instead cut herself a reimbursement check from his campaign fund to cover the costs.

But Williams' lawyer, Thomas Burke, has pushed back against Montgomery's account and any suggestion that Pennsylvania's loose campaign finance laws would bar the types of personal expenses his client now stands accused of making with campaign cash.

Burke has sought to block Montgomery as a witness, calling her unqualified despite her decade of experience as one of the state Democratic Party's top fund-raisers and financial managers.

"The expenditures were consistent with the well-established practice of elected officials in Pennsylvania," he wrote in a recent filing. "Even a cursory review of the publicly available campaign finance reports for many of Pennsylvania's well-known past and present elected state officials reveals comparable expenditures."

But Zauzmer, the prosecutor, bristled at that argument in a response filed Friday.

Williams, he wrote, "is free to argue to the jury that the allegedly improper expenses such as 'deep pore facials,' birthday massages for Williams, and women's leggings were proper campaign expenditures."

Williams has deployed similar arguments to push back against prosecutors' claims that he violated policies on city car use by treating government vehicles as his own personal fleet to ferry his daughters and friends on personal trips, including a 2014 excursion to a Virginia resort.

As district attorney, his lawyer has argued, Williams was not subject to the policies he imposed on his staff and had full authority to change them at any time.

But prosecutors hope to show jurors that, earlier in his career, Williams relished his role as a chief enforcer of those policies while serving as the city's inspector general between 2005 and 2008.

During that tenure, he investigated and reported city employees on numerous occasions for taking government cars home, often subjecting workers who broke the rules to discipline including suspension without pay.

Even after he had left the job, Williams continued to report offenders.

"I can't stop myself," he wrote in a 2008 email to his former secretary in the office. "It is 8:40 p.m. I am in the Lord & Taylor parking lot in Bala Cynwyd and a city-owned minivan is here."