A Milan appeals court on Saturday set Silvio Berlusconi's political ban in his tax fraud conviction at two years, setting the stage for more wrangling over the future of the embattled politician who continues to wield political influence.

The appellate court was ordered by Italy's highest court to determine the length of the political ban accompanying his tax fraud conviction and four-year jail term after prosecutors conceded sentencing errors in the original five-year ban.

It is one of two political ban processes set in motion when Berlusconi lost his final appeal in August over his tax fraud conviction and a four-year jail sentence. Since both political bans need to be approved by Parliament, the process of enforcing them promises to be lengthy.

Berlusconi already is facing the loss of his Senate seat due to the conviction under a 2012 law stipulating that anyone convicted to more than two years in prison cannot hold or run for office for six years. A Senate committee has approved yanking his seat, but a vote by the whole chamber is pending and could come before the end of the year.

Berlusconi's defence lawyer, Nicolo Ghedini, immediately pledged to appeal the two-year ban to the nation's highest criminal court. The moves could be rendered futile if the six-year ban is already in place.

For now, the three-time former premier and his centre-right forces have pledged to continue their support for Premier Enrico Letta's cross-party government of long-time political foes on the left and the right. After triggering a government crisis by threatening to pull his party's backing, Berlusconi did a last-minute about-face to support the government in a confidence vote.

The political bans would bar Berlusconi from participating in new elections for their length, but he could remain the titular head of his party without holding political office.

Berlusconi won't do jail for the tax fraud case. The four-year term has been reduced to one year under an amnesty for crimes committed before 2006, and Berlusconi reportedly has requested to perform community service instead of house arrest.

Berlusconi also faces a seven-year sentence and lifetime political ban after being convicted this summer of having paid a minor for sex and forcing officials to cover it up. He has two appeals. A Naples court also is investigating him for allegedly bribing a lawmaker to bolt a previous center-left government under Romano Prodi.