* Czech Senate approval brings Lisbon Treaty closer
* President Klaus says he will not ratify for now
* All eyes now on Irish referendum later this year
(Recasts, adds Merkel comment, analyst)
By Jan Korselt
PRAGUE, May 6 (Reuters) - The Czech upper house approved the European Union's Lisbon reform treaty on Wednesday, putting the onus for its adoption squarely onto the Irish voters who will hold a referendum later this year.
The eurosceptic Czech president, Vaclav Klaus, made clear he would not ratify the parliamentary vote unless the Irish, who have already rejected the treaty once, vote 'Yes' this time.
The Lisbon Treaty is meant to simplify decision-making in a Union that has grown from 15 to 27 members since 2004.
It has already been ratified by 23 other EU states, and would give the bloc a beefed-up foreign representative and a long-term president, remove national vetoes on some decisions and raise the voting power of big EU states.
Klaus, a long-term opponent of closer European integration, said he would not sign the treaty, already approved in the lower house, pending an expected court challenge against it in the Czech Republic's highest court and the new Irish vote.
But the result of the Senate vote, which had been in some doubt because of a strong eurosceptic faction allied to Klaus in the upper house, was a major step forward for the treaty.
"With today's vote, parliament clearly indicated that the Czech Republic wishes to continue to play a central role in the European integration process within the EU," said Deputy Prime Minister Alexandr Vondra.
Klaus and some lawmakers in the ruling right-wing Civic Democrats say the treaty erodes national sovereignty and is a step towards a European superstate.
He said he would wait for a group of eurosceptic senators to file a constitutional complaint against the charter, and for the judges to rule. The court has already cleared the document once.
"The Lisbon Treaty is dead for this moment. It is dead because it was rejected in a referendum in one member state. Therefore, a decision on ratification of this treaty is not on the agenda at this point," Klaus told reporters.
EYES ON IRELAND
Analysts said Klaus wanted to boost the 'No' camp in Ireland ahead of the repeat vote there planned for the autumn.
"He can try to relieve pressure on others that could be applied by using the argument 'Everyone has ratified and we are only waiting for you'," said Josef Mlejnek, a political science lecturer at the Charles University.
"If the Irish approve the treaty, he will not dare kill it."
Klaus himself said last year that he would not be the last man in Europe to stand in the way of the treaty.
The Lisbon Treaty also still lacks the signature of Polish President Lech Kaczynski, and ratification from Germany, where it also faces a Constitutional Court challenge.
German Chancellor Angela Merkel said the Czech Senate vote was significant.
"Today I think we got a good deal closer to getting this treaty through and implementing it," she said in Berlin.
"And now we have the opportunity of talking to the Irish government in June about how a second referendum can be held."
European Commission President Jose Manuel Barroso said prospects for the Irish vote looked brighter after the Czech Senate vote, and that he believed Klaus would sign the pact.
Outgoing Czech prime minister Mirek Topolanek has signed the charter, arguing that approving it was better than risking an erosion of the EU, which would expose the former Communist country to Russian influence.
"I do not accept the Lisbon Treaty with any great euphoria," he told the Senate ahead of the vote. "But I take it as a price for membership in the club." Rejection would "chase us into Moscow's sphere of influence", he said.
Topolanek's cabinet will hand power to a caretaker administration on Friday after losing a no-confidence vote in March, halfway through Czech presidency of the EU.