ANKARA, Feb 6 (Reuters) - If a top court bans Turkey's only legal Kurdish party, millions of Kurds will still wage a peaceful struggle to gain wider cultural rights, the party's chairman said in an interview on Wednesday.

"There are millions behind us. You can close the party, ban its leaders, but those millions won't disappear," said Murat Bozlak, who heads the People's Democracy Party, or HADEP.

"They will not leave the path we have set," he told Reuters.

The Constitutional Court is weighing charges to ban HADEP for allegedly serving as a front for the separatist Kurdistan Worker's Party (PKK). HADEP denies the charges.

Bozlak, facing up to 22 years in prison on related charges, said he believed recent reforms to Turkey's constitution, originally drawn up under military rule in the 1980s, may convince the Constitutional Court to spare his party.

The case is the first test of the constitutional reforms, designed to meet European Union criteria that include making bans on political parties more difficult.

The EU has urged Turkey to expand civil liberties for its 12 million Kurds to smooth the way for talks about Ankara joining the bloc. It says party bans stifle democratic debate and encourage the disaffected to seek ever more radical outlets.

State prosecutors filed the case against HADEP in 1999 when fighting still raged between Turkish soldiers and the PKK, which launched a guerrilla campaign in 1984 for self-rule in mainly Kurdish southeastern Turkey. More than 30,000 people have been killed in the violence.

DEATH ROW

Fighting has largely ended in the southeast since commandos captured PKK commander Abdullah Ocalan in 1999. From death row, Ocalan has called on PKK fighters to withdraw from Turkey and seek rights for Kurds through political means.

"This (case) is because we said, 'Kurds exist'. That may have been enough to shut us down in the past, but it no longer means we should be closed," Bozlak said.

"The previous tension in Turkey and the ensuing political motivation to shut us down have passed," he said.

Turkey prohibits parties from setting up along religious or ethnic lines and has banned about 20 parties since the 1960s, including three of HADEP's predecessors. Last June, the Constitutional Court outlawed parliament's main opposition, the Islamist Virtue Party.

Many outlawed parties have simply regrouped under new names.

Despite the relative peace in the southeast, flashpoints still erupt over the Kurdish issue. Police last month detained hundreds of university students and parents who signed petitions calling for Kurdish-language instruction in schools.

Last year's constitutional amendments lifted a ban on Kurdish TV and radio broadcasting, but authorities fear allowing the Kurdish language in the classroom could undermine national unity.

HADEP won less than the 10 percent of votes needed to enter parliament in 1999 elections, but has topped polls in the southeast and holds several large mayoral offices in areas governed by emergency rule since 1987.

The powerful military has voiced concerns about HADEP's popularity in the impoverished southeast.

"Turkey doesn't have a tradition of diversity. It has a tradition of closing down parties," Bozlak said.

"Our fundamental purpose has been to try and solve the Kurdish question, one of Turkey's most painful issues. No one else discusses this issue, let alone does anything," he said.

During the height of the guerrilla conflict, HADEP activists faced regular police detentions and political bans. Bozlak has already been imprisoned for three years.

If HADEP escapes closure, its leaders must use their new-found freedom to widen the party's base and pass parliament's threshold -- or face elimination at the polls.

"It is natural that Kurds support us. But we must work to represent all of Turkey," Bozlak said.