By Richard Balmforth
KIEV (Reuters) - EU negotiators flew to Ukraine on Tuesday in what looked like a final attempt to secure the release of jailed opposition leader Yulia Tymoshenko, but parliament was far from agreeing a law that could allow her go to Germany.
Further souring the atmosphere for a deal on Tymoshenko that could ensure the signing of landmark agreements with the European Union at a summit on November 28, a row erupted over criminal proceedings brought against her defense lawyer.
With parliament deadlocked over Tymoshenko's release, it seemed possible that the EU negotiators - Irish politician Pat Cox and former Polish President Aleksander Kwasniewski - might return on Wednesday without any clear summit-saving formula.
The accords on association and free trade, due to be signed at an EU-Ukraine summit in the Lithuanian capital Vilnius, offer the former Soviet republic the chance of a historic shift westwards away from Russia.
President Viktor Yanukovich has stuck to his policy of Euro-integration despite intense diplomatic pressure from Russia - on which Ukraine relies for gas - and threats of retaliatory trade action by the Kremlin.
But success at Vilnius hinges on him freeing ex-prime minister Tymoshenko, his fiercest opponent. She was jailed in 2011 for seven years for abuse of office after a trial which the EU says was political.
Yanukovich, who only narrowly defeated her in a run-off in February 2010, has refused to pardon her, fearing she could stage a comeback to spoil his chances of re-election in 2015.
But, under pressure from the EU, he has said he will sign any draft law from parliament that would allow his adversary to go to Germany for medical treatment to her back.
Parliament is due to hold a special session on Wednesday but pro-Yanukovich deputies, who dominate the assembly, have been unable to agree the wording of a law that would allow Tymoshenko to leave for Germany, opposition lawmakers said.
The 28-nation EU has pressed Ukraine to meet basic democratic criteria to demonstrate its readiness for an association agreement. One of these is an end to "selective justice" which they say was applied against Tymoshenko.
Cox and Kwasniewski, who have shuttled in and out of Kiev over 18 months, headed there on Tuesday night in what a European Parliament official described as "a last-ditch effort to help resolve the Tymoshenko case."
They were due to return to Brussels on Wednesday and give an indication of their findings at an evening news conference.
EU foreign ministers are due to hold a pre-summit meeting on November 18 to assess whether Kiev has met the key criteria.
The bloc itself is split between states such as Poland, which stress the need to prise Ukraine away from Russia's embrace, and those like Sweden and the Netherlands, which say the bloc should not compromise on civil rights and justice.
But opposition lawmakers said parliamentary factions had failed to agree on the wording of a law to let Tymoshenko go.
Yanukovich's supporters want her to be simply released for treatment and then to return to Ukraine to complete her sentence. The opposition is pushing an option under which her sentence could be wiped out after treatment.
Meanwhile, a row erupted over a criminal investigation launched against Tymoshenko's chief lawyer. Serhiy Vlasenko, who has been the main conduit of information about Tymoshenko from the hospital where she is being held under prison guard, was bailed on Tuesday on suspicion of beating his wife.
The 52-year-old politician, in a message from hospital in the town of Kharkiv, accused Yanukovich of being behind the "absurd charges" against Vlasenko and said he was trying to "kick to death" the impending agreements with the EU.
Yanukovich has not spoken on the Tymoshenko case for some weeks. But deputies in his Regions Party has shown signs of toughening their position on whether she should be released, and some now suggest Ukraine could forego the EU deal.
"If we don't sign association with the EU, it will be bad - for both Ukraine and for the European Union," said Oleksander Yefremov, head of the Regions faction in parliament.
"But it won't be the end of the world. The sun won't stop coming up. But at least we'll have our self-respect, knowing that we are a state and not somebody's puppet."
(Additional reporting by Justyna Pawlak and Adrian Croft in Brussels; Natalya Zinets and Pavel Polityuk in Kiev; Editing by Robin Pomeroy)