"More than a year ago the government began its own campaign and the opposition hasn't taken any initiative," Chebbi told reporters.

Chebbi is the first top official from a political party to announce he will be a candidate in the election.

It was important now to put pressure on the government to make social and economic reforms", the 60-year-old lawyer added.

Chebbi was prevented from running in 2004 elections as his party did not have a seat in parliament.

"I think that the acceptance of my candidacy will be a way to assess whether the government is ready to run a fair and pluralistic election."

"If a political party is excluded ... it will be

confirmation that the government wants only decorative pluralism and not free elections," Chebbi said.

Supporters have been calling on Tunisian President Zine al-Abidine Ben Ali to stand for re-election. But Ben Ali has not commented on whether he will be a candidate.

Chebbi, who handed over to Maya Jribi, the first woman to lead a Tunisian political party, says he will focus his campaign on unemployment, purchasing power and demands for political reform.

Ben Ali gained power in 1987 when doctors declared the then president Habib Bourguiba senile and unfit to rule. A referendum in 2002 revised the constitution to allow the president an unlimited number of successive five-year terms.

Ben Ali won 94.4 percent of vote in the last election.