(WARSAW) - Polish President Lech Kaczynski's refusal to sign the EU's Lisbon Treaty because of Ireland's "No" vote is rooted in an enduring domestic battle with Prime Minister Donald Tusk, analysts said Tuesday.

The two men were thrust into an unhappy working relationship last October when the liberal Tusk trounced the conservative Jaroslaw Kaczynski, the president's identical twin, in a snap election.

For the past eight months, Tusk and Kaczynski have been wrangling over who drives the policy agenda, notably foreign relations.

In an interview published Tuesday by the daily Dziennik, the president was quoted as saying that "for the moment, the question of the treaty is pointless" because of the Irish "No" in a June 12 referendum.

Poland's parliament voted in April to ratify the Lisbon Treaty -- a key accord meant to streamline EU decision-making and which must be approved by all 27 member states -- but the presidential seal of approval is still needed.

Tusk criticised Kaczynski on Tuesday, saying he hoped the president would go back on his announcement.

"This isn't the way to build Poland's standing in the world," he said.

Kaczynski has the upper hand, said Piotr Winczorek, a constitutional law expert from Warsaw University.

"Neither parliament nor the government has any room for manoeuvre," because there is no way to overturn a Polish president's refusal to sign a treaty, Winczorek told AFP.

For Lena Kolarska-Bobinska, director of Poland's Institute of Public Affairs, Kaczynski's move "has to be seen as part of an internal political game".

"He's a very partisan type of president," with a tough message for the often eurosceptic and deeply Catholic supporters of the opposition Law and Justice party, run by Jaroslaw Kaczynski, Kolarska-Bobinska told AFP.

"This is a good occasion to mobilise its electorate," given that polls for the European Parliament are only 11 months away and that surveys show the twins are among Poland's most unpopular politicians, she added.

Kaczynski beat the liberal, europhile Tusk in the 2005 presidential election, shortly after Law and Justice had defeated Tusk's Civic Platform in parliamentary polls.

With Lech as president and Jaroslaw as prime minister, the twins won a reputation for confrontation at home and abroad, notably in talks with fellow EU leaders.

The Kaczynskis argued that they were simply defending Poland's interests.

But their tough approach, notably towards neighbouring Germany, and their hardball style at home turned off many Poles who then elected the smoother Tusk in last October's parliamentary elections.

At the time, other EU leaders breathed an ill-disguised sigh of relief, because the Kaczynskis had made repeated threats to sink the Lisbon Treaty during negotiations last year -- before finally approving it and then trumpeting a victory for Poland.

The Kaczynskis and Tusk had also sparred over April's ratification vote.

The twins attacked the Charter of Fundamental Rights, tied to the Lisbon Treaty, claiming it could pave the way for gay marriages in Poland and the restitution of properties lost by Germans after the Polish-German border was redrawn by World War II's victorious Allies in 1945.

Poland, like Britain, secured an opt-out from the charter during the treaty talks last year, and the Kaczynskis accused Tusk of failing to protect it.

But they finally backed off from torpedoing ratification in parliament after Tusk raised the spectre of a referendum -- which polls showed he would win.

"We're likely to see a new political crisis," said Kazimierz Kik, of the Institute of Political Sciences in Kielce, southern Poland.

Kik said that Kaczynski was aiming to force Tusk to agree that Poland's EU-related decisions be made jointly by the government, parliament and president, rather than just the government as is the custom.

"If Lech Kaczynski signs the treaty it will be a victory for Tusk. So the president wants his own victory by winning concessions from the liberals," Kik said.

Text and Picture Copyright 2008 AFP. All other Copyright 2008 EUbusiness Ltd. All rights reserved. This material is intended solely for personal use. Any other reproduction, publication or redistribution of this material without the written agreement of the copyright owner is strictly forbidden and any breach of copyright will be considered actionable.