By Francesco Guarascio

BRUSSELS (Reuters) - The European Commission on Wednesday gave Poland three months to boost the powers of its Constitutional Tribunal, stepping up pressure on Warsaw's euroskeptic government to respect the EU's democratic standards.

Commission deputy head Frans Timmermans said Brussels, with these new recommendations, was taking the next step in a disciplinary procedure that could lead to the suspension of Warsaw's EU voting rights and the freezing of its EU funds.

The move comes after months of largely fruitless diplomacy since Poland's Law and Justice (PiS) party won elections last October and imposed changes on the tribunal and Poland's public broadcaster, which Brussels fears undermine democratic checks and balances.

Following EU and U.S. pressure, the Polish parliament last week passed a new law on the tribunal that fell short of addressing concerns raised by Brussels.

"Despite the dialogue pursued with the Polish authorities since the beginning of the year, the Commission considers the main issues which threaten the rule of law in Poland have not been resolved," Timmermans told a news conference.

Brussels urged Poland to take "appropriate action to address this systemic threat to the rule of law," a Commission note said.

Poland's foreign ministry said the requests were premature. "The law on the Constitutional Tribunal, which is entering the last phases of the legislative process, is to introduce various systemic solutions which are entirely in line with European standards of constitutional court functioning," it said.

Poland's 1997 constitution gives the tribunal power to block laws approved by parliament and the president, but the PiS -controlled parliament passed laws in December saying that court verdicts must be passed by a two-thirds majority, instead of a simple majority.

Last week, after EU pressure, the Polish parliament voted to remove the requirement for a two-thirds majority but introduced a clause giving judges the power to postpone a ruling by six months if four judges agreed.

Timmermans acknowledged that the removal of the two-thirds majority was a step in the right direction, but stressed that other measures were needed and some amendments made things even worse.

"New problematic provisions have been introduced in the legislative process on the functioning of the tribunal, raising concerns on the effectiveness of constitutional review," he said.

The Commission urged Poland to publish the tribunals' recent rulings, which has not yet been done, preventing them from going into effect. It specifically mentioned a tribunal ruling that the new changes to its procedures are unconstitutional.

It also said that any reforms of the tribunal must not undermine its powers.

Brussels also called on Poland's President Andrzej Dudas to swear in the three judges of the 15-strong Constitutional Tribunal chosen by the previous parliament but replaced by PiS members.

(This story has been refiled to fix name spelling)

(Reporting by Francesco Guarascio and Marcig Goettig in Warsaw; Editing by Philip Blenkinsop and Tom Heneghan)