Berlusconi appealed to the Strasbourg-based court in 2013 after a criminal conviction for tax fraud triggered a six-year ban from public office. The beleaguered former prime minister has denied all wrongdoing and his lawyers are hoping a lifting of the ban will mean he can run in the next Italian election expected to take place in early 2018.
The media tycoon's political career was widely regarded to have ended in 2011 following a string of scandals. Berlusconi was forced to resign as prime minister amid a sex scandal involving his "bunga bunga" parties, while Italian bond yields were skyrocketing at the height of the euro zone debt crisis.
After recovering from open heart surgery in 2016, the 81-year old politician known as the 'Comeback Kid' by his supporters has yet again returned to the political arena. And as head of the "Forza Italia" party, he is seeking to form a center-right coalition in the national ballot next spring.
Somewhat surprisingly, Berlusconi's political revival is currently viewed as "a force of stability" by financial markets, Valentijn van Nieuwenhuijzen, chief investment officer at NN Investment Partners, told CNBC Wednesday.
"Anything that does not lead directly to Italy voting to move out of the euro zone will probably be seen by markets as not disruptive enough to worry about," he said.
At the start of the month, the four-time prime minister received a timely boost to his hopes as he secured victory in a regional ballot in Sicily. The regional elections were seen as an important barometer for Italy's voting intentions next year.
Berlusconi has argued his ban on returning to public office violates his rights under the European Convention of Human Rights.
The "Berlusconi versus Italy" case, which begins Wednesday morning, will be heard by 17 judges who make up the Strasbourg court's Grand Chamber. This court is typically used for highly important or particularly complex matters.
The court will not issue a verdict Wednesday though even if the Grand Chamber rules in favor of Berlusconi, a decision to lift the ban may not come in time for him to run in the election.
Italy's national vote must be held before May next year.