Stanislav Gross is a popular young politician

President Vaclav Klaus officially backed Mr Gross' appointment to replace Vladimir Spidla, who stepped down last month.

Mr Gross, the Social Democrats' acting chairman, is expected to form a cabinet by 1 August from the same coalition that made up Mr Spidla's government.

The appointment would make Mr Gross, at 34, Europe's youngest prime minister.

Mr Spidla stood down in June following the Social Democrats' heavy losses in the European elections.

Last week, Mr Gross said the major priorities for a new administration had been agreed.

Mr Gross has spent more than three weeks negotiating in order to preserve a coalition government made up of Social Democrats, Christian Democrats and the Freedom Union party.

The Czech Republic is due to hold general elections in 2006.