Noting that his client had already paid back taxes and penalties over the affair, lawyer Jean Veil said he had "no desire to see my taxes going towards maintaining Jérôme Cahuzac" in jail.
The 64-year-old former rising star in the French Socialist Party was also accused of under-declaring the value of his fortune when he took up his post in 2012 with a remit that included fighting tax fraud.
Prosecutors say he should be jailed for three years, while demanding a two-year prison term for his co-defendant and ex-wife, dermatologist Patricia Menard.
The verdict is set for 8 December.
The pair, who ran a lucrative hair transplant clinic that treated members of Paris's high society, have already paid back taxes and penalties totalling some 2.5 million euros.
Prosecutor Jean-Marc Toublanc described a "family life that was rooted in fraud for 20 years".
Luxury apartments and holidays
Cahuzac, a trained plastic surgeon, told the court that he stashed funds offshore to maintain his family's standard of living - which included buying luxury apartments for the children in London and Paris and paying for expensive holidays in Mauritius.
The story of the fraud, allegedly perpetrated between 1992 and 2013, reads like a cross between a cheap airport novel and an international financial crime manual.
In one episode, Cahuzac, using the codename "Birdie", allegedly received two cash payments of 10,000 euros each on the streets of Paris.
The couple used a Royal Bank of Scotland account in the Isle of Man, an offshore financial centre in the Irish Sea, to channel cheques from English hair transplant clients through the company the couple set up in 1997.
Later, as their marriage began to falter, Menard also opened an account in Switzerland.
Menard's lawyer Sebastien Schapira said the money was "that of fraud, but initially it was that of her work, earned day after day, hour after hour, hair by hair".
He described Menard as "naive", an unwitting accomplice who was "swept up" in the fraud before confessing to it in December 2013.
She testified that the couple had descended into a "spiral" of wrongdoing.
"We were very aware of the illegality," she said, adding: "I'm extremely ashamed of having done all that."
The scandal was the first of a series that have tarnished Francois Hollande's presidency and prompted him to order his ministers to disclose their personal wealth, a first in France, where the wealth of public officials had long been considered a private matter.
Cahuzac initially denied the allegations and sued the Mediapart news website that broke the story in 2012.
Footage of the minister lying to parliament was repeated in an endless loop on French media after he finally confessed in April 2013, "consumed by remorse", to holding a Swiss bank account.
Swiss bank account
The two-week trial opened with a sensational -- and unsubstantiated --claim by Cahuzac that he first opened a Swiss bank account in 1992 to "finance the political activities" of Michel Rocard, the former French prime minister who died in July aged 85.
But by the end of the trial, Cahuzac had repeatedly expressed remorse over his "inexcusable wrongdoing", tearfully referring to his "conjugal shipwreck" and his betrayal of friends and voters.
Also in the dock were the couple's advisers, Swiss banker Francois Reyl and Dubai-based lawyer Philippe Houman, as well as the Reyl bank of Geneva, which in 2009 allegedly helped Cahuzac transfer funds to Singapore to avoid detection by French tax authorities.
Reyl and Houman face suspended prison sentences and fines if convicted.
- with AFP