Leader of Law and Justice party Jaroslaw Kaczynski speaks during an interview with Reuters in party headquarters in Warsaw, Poland December 19, 2016. REUTERS/Kacper Pempel(reuters_tickers)
By Justyna Pawlak and Andreas Rinke
WARSAW (Reuters) - German Chancellor Angela Merkel will meet Law and Justice party (PiS) leader Jaroslaw Kaczynski, seen as Poland's main decision-maker, on Tuesday amid signs the Warsaw government is keen to restore co-operation to counter several challenges
Merkel needs the backing of Poland's government, wary of any increased powers for Brussels, to agree to reforms in March -- the same month Britain plans to give notice of leaving the European Union.
Ties were frosty when the PiS last governed Poland, between 2005-07, with Kaczynski making criticism of Germany central to campaigning to bolster the party's nationalist message.
But diplomats say Poland is feeling under pressure with Britain's decision to leave depriving it of an ally within the EU. Donald Trump's election as U.S. President is also raising questions over the West's relationship with Russia, which Poland sees as its arch-enemy.
Kaczynski holds no government posts but wields great influence. Once deeply-suspicious of Merkel, he is likely to be
keen to see her win another term this year due to concern that Poland's relations with Germany would suffer if Social Democrat candidate Martin Schulz beats her in the election.
"Merkel would be the best for us," he told Frankfurter Allgemeine Zeitung newspaper. "Especially now that Mr. Schulz is challenging her."
"People who want important positions should be able to control themselves. Mr. Schulz is not known for that, but for attacks and shouting."
Schulz drew ire from the Polish government in 2015 when he said its refusal to accept people fleeing war in the Middle East and North Africa would show a lack of European solidarity.
Interior Minister Mariusz Blaszczak, in turn, had accused Schulz of "German arrogance" and said Germans should not criticize Poland after killing tens of thousands of Poles during World War Two, invoking a line frequently used by the PiS.
Talk of Nazi atrocities has died down in recent months and meetings at various levels of government have become more frequent.
"I can imagine that Poland is feeling vulnerable in the current environment, with Trump making overtures to Russia and Britain leaving the EU," a German diplomat told Reuters. "This could push them towards Germany."
Poland had long seen Britain as its key ally in pushing a tough line on Russia over its conflict with Ukraine and in defence cooperation. The PiS had also hoped to find a partner in Britain for its calls to weaken the power of EU institutions.
Obstacles to finding common ground in Tuesday's talks with Merkel include Poland's hostility to resettling refugees from the Middle East, and international accusations that Kaczynski's government is veering into authoritarianism.
However, Poland and Germany are keen to see more EU defence cooperation after Britain's departure and a strengthening of the bloc's external borders.
Kaczynski has met few foreign leaders since the PiS returned to power. His talks with Merkel, set to start at 6 p.m. (1700 GMT), will take place in the shadow of Kaczynski's deep-running mistrust of Germany and of Merkel.
In his 2011 autobiography, Kaczynski accused her of seeking to "subordinate" his country to Germany.
"There is no doubt that Merkel belongs to a generation of German politicians who want to rebuild Germany's imperial power," he wrote. "Our country has to be in some way subordinate."
In a veiled criticism of the PiS, Merkel also meets opposition leaders in Warsaw.
(Additional reporting by Lidia Kelly and Pawel Sobczak in Warsaw, and Noah Barkin and Andrea Shalal in Berlin, Writing by Justyna Pawlak, Editing by Angus MacSwan)