Ukraine has stepped up efforts to dismantle the country's main opposition party after initialing a political and trade agreement with the EU.

Diplomats from both sides at a ceremony in Brussels on 30 March formally sealed the content of the 1,000-page-long treaty after more than four years of negotiations.

The Ukrainian foreign ministry at the time said it expects EU leaders to sign the text in six to 12 months' time. Its head of EU integration, Yevhen Perelyhin, said on national TV on Monday (9 April), Ukraine should start getting ready for the "versatile opportunities" offered by the trade part of the deal.

For its part, the EU back on 30 March published a laconic press release to mark the event.

EU diplomats say the Union initialed the treaty in order to show President Viktor Yanukovych that the door remains open to improving relations. But at the same time, they have watched with dismay as he continues to smash up the country's main opposition party in the run-up to parliamentary elections in October.

The prospect of freeing former leader Yulia Tymoshenko in time to register as a candidate for the vote diminished in the past two weeks with the launch of a new PR campaign to link her with a gangland murder.

Ukraine's deputy general prosecutor Rinat Kuzmin told the Financial Times on 1 April that a bank account controlled by Tymoshenko was used to pay the killers of Yevhen Shcherban, a businessman shot dead in eastern Ukraine in 1996. The dead man's son, a pro-Yanukovych MP, made similar claims at a press conference in Kiev on 4 April.

Kuzmin on 7 April said on Ukrainian TV that the current head of Tymoshenko's party, Oleksandr Turchynov, should face trial for allegedly bribing a journalist.

Courts last week also jailed for three years Georgiy Filipchuk, Tymoshenko's former natural resources minister, on charges of abuse of power while in office. On Monday, prosecutors said her former acting defence minister, Valeriy Ivashchenko, should go to prison for six years on corruption charges.

Tymoshenko last week and her daughter Eugenia Carr, in an earlier interview with EUobserver, have called the contract killing allegations "absurd."

For his part, neighbourhood commissioner Stefan Fuele has said the EU will only sign the association treaty if the October elections are free and fair.

But the EU has not made explicit whether this means only that the vote-count is not faked, or whether it also means that Tymoshenko and her party must be allowed to compete under normal conditions.