Graham Stack in Kyiv -

Jailed opposition leader Yulia Tymoshenko is opposed to any deal between the opposition and embattled President Viktor Yanukovych to end a mass protest movement that has occasionally erupted in violence, according to a letter sent from her jail cell to her parliamentary group, and subsequently leaked to the public.

The firebrand former prime minister Tymoshenko, two and half years into a seven-year jail sentence, made a powerful intervention on February 4 in talks between opposition and government on an exit to the current crisis, which arose when Yanukovych failed to sign a deal in November that would bring Ukraine closer to the EU. Tymoshenko dispatched a six-page letter to the parliamentary group of her Batkvyshina party, in which she poured scorn on the united opposition's joint platform for talks with Yanukovych.

In particular she rejected the plan to switch from the current presidential constitution - which Yanukovych created for himself in 2010 and which endows him with far-reaching powers - to the original 2004 semi-presidential constitution, where the government is responsible to parliament. Parliament is currently debating the issue, with the opposition calling for a vote on it this week.

Under huge international and domestic pressure, Yanukovych has shown flexibility in bowing to the demands of the opposition, after protests turned violent in January. Thus far, he has repealed the repressive laws - nicknamed by opposition the "laws on dictatorship" - that triggered the violence, agreed to an amnesty for protestors, sacked the government, and consented in principle to reverting to the semi-presidential constitution, although the time frame is still being hammered out behind doors. The three main opposition parties have made constitutional change a condition for joining a government of national unity.

Tricky Victor

But this flexibility on the part of Yanukovych has aroused the suspicions of Tymoshenko, who has every reason to be leery of him: after losing narrowly to him in presidential elections in February 2010, she was subsequently jailed on what are widely regarded as trumped-up charges of having exceeded her powers during her time as prime minister. She has repeatedly warned of the threat he poses to Ukraine's fragile democracy.

According to the letter, leaked by a pro-government Party of Regions MP on his Facebook page: "It is not entirely clear to me why opposition and civil society have started to play according to Yanukovych's plan demanding return to the 2004 constitution," Tymoshenko wrote. " I see that the government... has suggested this as a path out of the crisis as a trick."

"Yanukovych is simply considering variations of developments in 2015," Tymoshenko continued, in an analysis that suggests she remains a formidable tactician even behind bars. "Firstly, if he manages to falsify presidential elections (in 2015) and remain for another term, he will retain the existing constitution... If the opposition candidate becomes president in 2015, then before the inauguration Yanukovych will switch to the 2004 constitution, propose himself as prime minister and then there will be dictatorship and corruption - forever!"

Tymoshenko also argued against any participation in a national coalition government, calling this a "foolhardy gamble" that Yanukovych would use to discredit the opposition, by making them scapegoats for the disastrous economic situation in the country.

Sowing dissent

Tymoshenko's letter was gleefully leaked to the public by Oleg Tsarev, a Yanukovych loyalist MP in the Party of Regions. Tsarev was clearly hoping to sow strife among the opposition ranks and he has succeeded. Viktor Baloha, an influential independent MP in the opposition camp, wrote on Facebook: "(th)e propositions in (Tymoshenko's) letter are a purely Russian scenario. Who benefits? Ukraine, Maidan, citizens? No. We need what the Ukrainian people are demanding - a return to the 2004 constitution." Baloha said that Tymoshenko had made at least one opposition party "feel itself a victim of fraud."

The leak of Tymoshenko's initiative has sparked panic within her Batkvyshina party itself. Tymoshenko's letter addressed her MPs as "my commandos". But it is not clear who is really in command: the effective leader of Batkyvschina, head of the Batkyvschina parliamentary group Arseny Yatsenyuk, is a former rival of Tymoshenko, who merged his smaller party with Batkyvschina in 2013, and has since become one of the public faces of the protest movement.

MPs attempted damage limitation, saying they would visit Tymoshenko in jail to discuss the issue with her - whenever that is next possible, since prison regulations limit her visitors. They also noted that the letter, read to the parliamentary group February 4, had been written January 30, so it was already behind the times.

Tymoshenko's leaked letter may now force clarification of what power she wields from her cell. "It is clear that Batkyvschina is far from a monolithic political force and her opinion is just one of several. At the moment, it perhaps counts more what Yatsenyuk thinks," says Otilia Dhand of Teneo Intelligence.

But Yatsenyuk has to walk a tightrope. Tymoshenko is still the party's figurehead and possesses huge standing that has actually grown during her years in jail. This charisma is vital to the party's future electoral success. According to the most recent polls, if Tymoshenko were to run in presidential elections, she would take 14.6% of the national vote in a first round, giving her a chance of winning a run-off against Yanukovych. The technocrat Yatsenyuk, if he ran, would be left on the sidelines with only 6.3%.

Many Ukrainians who are against Yanukovych are dismayed by the caution of the parliamentary opposition when compared to the activism of the fire-throwing youth. They believe that, if free, Tymoshenko would have the balls to lead the protest movement to power, as she did in 2004 with the Orange Revolution, without entering into potentially treacherous power-sharing deals with Yanukovych.

This seems to be Tymoshenko's opinion too. "The most sure and effective way is to help Ukraine lead the uprising to victory, until the unconditional capitulation of Yanukovych," she told her MPs in the leaked letter. "I gave you a plan of action. Act! I believe that there is no way to end the dictatorship except by a peaceful all-encompassing popular uprising."