Brussels -- The European Commission last week rejected criticism from Italian Prime Minister Silvio Berlusconi, who is threatening to block EU business after Brussels questioned Rome's treatment of asylum seekers.

"When there are problems which affect a member state, such as Italy, we must ask for a number of explanations, information, that's what we did early this summer," EU Justice Commissioner Jacques Barrot said, adding he was awaiting a reply.

The row centres around reports that Italian coastguards on Sunday turned back a boatload of 75 migrants off the coast of the island of Sicily.

The migrants, thought to be Somali, were travelling in a rubber dinghy which was intercepted by coastguards around 44 kilometres (27 miles) from Sicily's shores.

The group, which included 15 women and three children, was transferred to an Italian police patrol boat and sent back immediately to Libya.

Berlusconi on Tuesday reacted angrily to the European Commission's enquiries into the incident.

The "voice of Europe," he said, must be expressed exclusively by the president of the commission or his immediate spokesperson. If this did not happen, he added, he would "block the functioning of the European Council."

Speaking on the margins of a commemoration of the start of the Second World War 70 years ago, he called on EU commissioners and their spokespeople not to "publicly intervene any more on any issue".

Only commission chief Jose Manuel Barroso and his spokesman should be allowed to comment, Berlusconi said, speaking in the Polish city of Gdansk.

"If commissioners and spokesmen continue as they have done all these years, they should be fired in a definitive manner," he said. Otherwise "we will suspend our vote, blocking the functioning of the European Council."

Barrot defended the functioning of the commission, which is the EU's executive arm and helps draw up legislation and monitor compliance with European Union rules.

"We are acting within our role... I don't think this merits dwelling on matters which I believe are irrelevant," he told reporters in Brussels.

Barrot defended a commission spokesman who had been dealing with the justice portfolio temporarily, saying he had only reminded the media that asylum seekers who are vulnerable should not be turned back without having their cases examined.

The EU Commissioner stressed that while no one was as yet criticising Italy, the problem with sending boatloads back was that they often had legitimate refugees travelling alongside illegal immigrants.

The EU Commissioner also strongly rejected Italian criticism that the European Commission was not doing enough to help countries such as Italy and Malta which are in the frontline of Europe's immigration problem given their proximity to Africa and the Middle East.