The European Union’s accident-prone efforts to modernise its institutions will pass an important milestone on Wednesday if, as expected, the Czech Republic ratifies the bloc’s Lisbon treaty in a parliamentary vote.

Mirek Topolanek, the outgoing Czech prime minister, hopes to leave office in a blaze of glory by securing the treaty’s approval and redeeming his country in the eyes of its critics, who have heaped scorn on its management of the EU’s rotating presidency since January.

Mirek Topolanek hopes to leave in a blaze of glory

But if the Czech senate, or upper house, were to reject the treaty, it would do still more damage to the nation’s reputation and throw the bloc’s future into even more uncertainty.

“I think the treaty will make it through,” AlexandrVondra, the Czech EU affairs minister, said on Monday.

Lisbon, though hardly a giant leap towards closer integration, aims to improve the EU’s ability to project its power by creating a full-time president and setting up a European diplomatic service. It will encourage more voting by majority rather than unanimity and expand the European parliament’s powers modestly.

But the treaty has been plagued with difficulties for four years. French and Dutch voters rejected an earlier version in referendums in 2005. The Irish did the same last June but will be asked to reverse their verdict in a second vote, probably in October.

In Prague, Mr Topolanek’s government pushed the treaty through parliament’s lower house in February.

But the agonisingly slow process of Czech ratification has frustrated other EU states, especially those in western Europe, which can hardly believe that, after almost a decade of attempts to redesign its institutions, the 27-nation bloc still does not know what rules will govern its activities from next January.

It has not helped that Vaclav Klaus, the Czech head of state, is a scathing critic of the treaty, although senate approval would leave him with little choice but to add his presidential signature and complete the ratification process.

The six-month Czech EU presidency came shuddering to a halt in late March with the fall of Mr Topolanek’s government and has failed to get a second wind since.

When the Czechs hosted a long-scheduled EU regional development meeting last month, only seven member states sent ministers.

“It is clear that the Czech Republic will continue administering the presidency until the end of June, but politically the Czech Republic has been really marginalised,” Jiri Pehe, a political analyst, told Czech radio.

Most EU governments are so desperate to see Czech ratification of the Lisbon treaty that they would happily forgive and forget much of the recent past if the senate were to vote Yes.

But as Mr Topolanek warned his fellow Czechs last week, failure to pass the treaty this week would push Prague to the EU’s sidelines and split the bloc into two camps – “the states that speak with each other and those that don’t”.