* Klaus may not demand new EU treaty ratification
* Most Czechs back Klaus's demand for opt-out
* PM Fischer says Klaus's actions damaging
(Adds Klaus's chancellor)
PRAGUE, Oct 16 (Reuters) - Czech President Vaclav Klaus may settle for a political rather than strictly legal guarantee from EU leaders that the bloc's new treaty does not reopen post-war property claims, news agency CTK reported on Friday.
Klaus stunned the Czech government and other EU members last week by demanding Czechs be granted an opt-out from the EU's Lisbon Treaty that would prevent property claims by ethnic Germans expelled from the country after World War Two.
The president is the only EU leader not to have signed into law the treaty, which aims to streamline decision-making in the 27-member bloc and give it more clout on the world stage.
EU leaders have invested years of effort into the pact, which would give the bloc a long-term president and foster further integration, and aim to bring it to life by January.
A Klaus aide said last week that Klaus would demand a strong and binding guarantee on the property rights, indicating he may want a change in the treaty that would require new ratification in all EU member states.
That would be extremely hard to achieve, with the approval process completed in all the remaining 26 EU states.
But Klaus's Chancellor Jiri Weigl said on Friday that there were other ways to meet Klaus's demands.
Prime Minister Jan Fischer has suggested that a way forward could be a political declaration by EU leaders, which would later be turned into legislation when EU members ratify the next treaty, which is likely to be the accession treaty with Croatia.
A similar guarantee was given to Ireland, reiterating that its neutrality, taxation and abortion laws would not be undermined by the Lisbon Treaty.
"We are discussing options how to meet this (demand). The president spoke about the Irish precedent and so on. It is all a matter of discussion not only between us and the government, but of course also with the EU," CTK quoted Weigl as saying.
Klaus's office had no immediate comment on the report.
CZECHS SHARE KLAUS'S FEAR
Klaus has struck a chord with voters in the Czech Republic, where anxiety over the post-war expulsion of the 3 million Sudeten Germans still surfaces from time to time.
A poll by the Median agency for the daily Lidove Noviny showed 65 percent of Czechs backed Klaus as they feared laws expelling Germans could be circumvented.
Families of the expelled Germans have demanded that the Czechs recognise it was wrong to use the principle of collective guilt in expelling the Germans.
Many of the Germans supported Hitler's Germany, which annexed the German-populated areas of Czechoslovakia under the Munich agreement in 1938.
Prime Minister Fischer told businessmen at a conference that Klaus's last-minute demand was seriously harming the republic.
"It is a very damaging matter, very harmful for the Czech Republic, let's admit this to ourselves," Fischer said.
Both houses of Czech parliament have approved the treaty.
Most lawyers and the government say Klaus's concerns are unfounded. Some analysts say Klaus, who has long been a fierce opponent of the treaty, is just being obstructive. (Reporting by Jana Mlcochova and Jan Lopatka; mediting by Ralph Boulton)