Belka was endorsed by the president

The lower house voted 262-188 against Mr Belka, who was appointed to replace Leszek Miller the day after Poland joined the European Union on 1 May.

He had appealed to MPs to give him a year to introduce reforms to fight poverty and improve healthcare.

Mr Belka will continue in a caretaker capacity until a new candidate is appointed in two weeks' time.

If that fails, President Aleksander Kwasniewski can propose a final candidate before he is required to dissolve parliament and call early elections.

Mr Belka, 51, may be asked again to form a government before any fresh election is called.

After Friday's vote, he said he said the result "was a little better than I expected".

"I'm an optimist."

On Thursday, Mr Kwasniewski urged parliament to support the new government, saying it would be a better solution to Poland's political crisis than early elections.

But parliament has been fragmented after defections from the ruling coalition.

Contract plea

"I ask for a contract of one year to accomplish a concrete task," Mr Belka told parliament before the vote.

"An economic revival accompanying EU membership is an exceptional opportunity. Not to profit from it would be unforgivable."

Miller saw Poland join the EU

He also asked for time to deal with Poland's involvement in Iraq, where it has 2,400 soldiers stationed.

He said he expected to be able to reduce troop numbers next year.

Mr Miller stepped down a day after Poland became the European Union's largest newcomer on 1 May.

The political turmoil comes as Poland is still trying to carve its international role and reach agreement on the new draft EU constitution.

Mr Belka has said he wanted to reach a deal before a key EU summit in June, whereas his predecessor fought to hang on to beneficial voting rights gained in the EU's 2000 Nice enlargement treaty.

Mr Belka, the former finance minister, resigned from the government last July amid reports he had objected to the rejection of his plans to cut the budget deficit.

After a short spell managing the international relief effort in Iraq, he was picked by US administrator Paul Bremer to spearhead Iraq's economic recovery.

Polish banks and businesses are said to trust the former minister, a liberal economist.