Franco Frattini, the European justice commissioner, is understood to have told the US that the EU was prepared to impose restrictions unless EU citizens in eastern Europe were allowed into the US without visas.

Travellers from all but one of the EU's new entrants have to apply for visas - only Slovenia is included in the visa waiver system.

Travellers from all but one of the EU-15, the union's members before the "big bang" expansion in 2004, are allowed to go to the US without visas. Only Greek citizens have to apply for visas.

A spokesman for the European commission said: "We hope that the visa waiver system is extended to all EU member states. The US's political recognition of the enlarged Europe should be recognised at a practical level."

Commission sources said they did not expect any change of heart by the US authorities, indicating that the "visa wars" may sour the atmosphere during a one-day EU/US summit in Vienna on Wednesday. Mr Bush hopes the summit will help to improve relations after disagreements over the Iraqi invasion.

One EU official said the US Congress appeared to be preparing to relax restrictions on Poland because its forces were supporting operations in Iraq and Afghanistan. "How many troops you have in Afghanistan and Iraq seems to decide visa policy," the official said.

US diplomats working in France, Greece and Spain already have to apply for visas. Any action would not apply to US diplomats in the UK, as Britain decides its own visa policy because it is not part of the border-free Schengen area of the EU.

He stressed the problems Italy has with the U.S. existed well before this spring's election, including Washington's refusal to fully cooperate with the Italian probe into the "friendly fire" shooting of an Italian intelligence agent, Nicola Calipari, in Baghdad.

Washington cleared its troops of any wrongdoing but refused to provide Italy with full details of its investigation.

D'Alema, who is also deputy premier and chairman of the Democratic Left party, explained that the Prodi government would seek to resolve differences with Washington "in a serious manner" taking into account "the strong ties of friendship between Americans and Italians and the principle of Italy's sovereignty".

During his meeting in Washington with U.S. Secretary of State Condoleezza Rice, D'Alema said that, aside from the Calipari case, he also broached the subject of the American prison camp for suspected terrorists at its Guantanamo base in Cuba.

Media reports suggested Tuesday's coordinated raids in the Sicilian capital of Palermo arose from matching the decoded notes with the results of an eavesdropping operation.

Investigators were reported to have recorded thousands of hours of conversation in a corrugated iron shack on the outskirts of Palermo, where Antonino Rotolo, one of those arrested in the latest raids, hosted meetings with associates.

Rotolo, who investigators say figured as 25 in Provenzano's numbered code, has for many years been under house arrest for medical reasons.

Reports, however, indicated that he was suspected of plotting the overthrow of the boss of bosses' reputed successor, Salvatore Lo Piccolo, 63, the alleged godfather of the Resuttana district of Palermo.

Previously it had been thought that Lo Piccolo's only serious rival for the top job in Sicily's mafia was a younger man, Matteo Messina Denaro, also on the run and known as the "playboy boss" because of his lifestyle.

Police were issued with 52 arrest warrants before the raids. Seven suspects were reported to have eluded capture. All the suspects for whom warrants were issued were accused of mafia membership. Some were also charged with extortion.

Rotolo, the reputed boss of the Pagliarelli district of Palermo, was first arrested for mafia-related offences in 1985. Reports yesterday indicated he had been in league with two other named suspects, a doctor and a builder.

By the time he was led from a semi-derelict farm building two months ago, Provenzano had spent more than four decades on the run. He was convicted in his absence and given life sentences for more than a dozen murders.

He is being held a top-security prison while prosecutors work on six other cases in which he is charged with offences ranging from murder to money-laundering.

The other will be a smaller aircraft seating around 15 to 20 people. The type of plane has yet to be decided.

Both will be on permanent lease and the extra cost of around £1.5m above the current £9.5m budget for air travel will be spread across several government departments including the Cabinet Office and the Ministry of Defence.

A senior No 10 source told the Press Association the current leasing system was "inefficient, becoming increasingly costly and not very secure".

Downing Street today refused to deny the news, saying it emerged from leaked documents and Number 10 practice was not to comment on leaks.

Earlier this month the influential intelligence and security committee recommended purchasing two dedicated aircraft for the prime minister and government, after a request from the former defence secretary, Geoff Hoon.

American presidents have had a dedicated aircraft since the second world war, although it was only under president John F Kennedy that the term "Air Force One" became popular.

The new plane will inevitably be dubbed "Blair Force One", although its cost has presumably been signed off the by the chancellor and possible future PM, Gordon Brown.

The news brought an immediate condemnation from the Conservatives - although not a clear indication as to whether they would scrap the planes if they took office.

The shadow transport secretary, Chris Grayling, said: "It sends totally the wrong message for ministers to be spending millions of pounds of taxpayers' money on two new, official planes at a time when jobs are being cut in the NHS.

"This reinforces the impression of a government which is out of touch with the real world, and is too concerned with the trappings of office rather than getting on with the job."

Sir Menzies Campbell, the Liberal Democrat leader, asked if the planes were either good value for money - or a green option.

He said: "The real question is whether these aircraft represent good value for the British tax payer. At the same time, we are entitled to ask what the prime minister intends to do to reduce the environmental impact of his travel.

"How often does he use scheduled services when it would be convenient to do so?"

Prime Minister Dominique de Villepin, who has faced repeated calls to resign over a dirty tricks scandal rocking the centre-right government, scored just four percent in the RTL, LCI, Figaro poll of voting intentions for next year's presidential race.

Jean-Marie Le Pen of the far-right National Front (FN) scored 12.5 percent in the telephone poll of 1.005 people conducted on June 14-15.

Royal, the new darling of the French media whose presidential bandwagon is swift gaining momentum, has recently upset some party traditionalists with her views on employment and crime.

In a text published on her website, Royal said the 35-hour working week, one of the flagship achievements of the last Socialist government in 1998, had had "mixed results for the quality of working life," the main argument put forward at the time for its adoption.

She has also outlined a tough plan to tackle youth crime that broke with the official Socialist position on security - but was approved by a great majority of the public, according to an IPSOS poll published in Le Monde.

Observers note that her public image has changed considerably in the past decade, going from bespectacled academic to designer-clad élégante.

Since the countdown began to the Socialist nomination in November, she has also worked on her voice - shifting from high-pitched, aggressive tones to deeper, sultrier ones, behavioural expert Georges Chetochine told Le Parisien newspaper earlier this month.

"She plays on her beauty - by wearing skirts rather than trousers, a youthful hair-style: who would think she is over 50?"

"She stands up very straight, holds her chin up - which makes her look highly determined and strong-willed. She looks like a women with a mission."

The FT business daily put their confidence down to a buoyant property market and strong economic growth.

Just nine percent of French respondents thought the country was moving in the right direction as it enters the final months of Jacques Chirac's 12-year presidency, ahead of elections in April.

Britons were nearly as glum, with only 21 percent saying things were on the right track and 66 percent finding the country headed down the wrong path, followed by the Germans and the Italians.

Europeans feel that the United States poses the biggest threat to global safety - more so than Iran, China, Iraq, Russia and North Korea - the poll showed.

The survey found that in Italy, France and Britain, more people favoured than opposed the construction of new nuclear power stations.

The FT said the results should provide some relief for British Prime Minister Tony Blair, who is undertaking a major energy policy review and supports a new generation of nuclear power plants.

Across the five countries, 44 percent were in favour while 43 percent were opposed.

The survey also found that Europeans thought it was too easy for foreign companies to take over businesses in their countries.

Concern over foreign predators was highest in Britain (68 percent), followed by Germany (57 percent), France (52 percent) and Italy (50 percent).

Harris Interactive interviewed 5,000 adults across the five countries between June 6 and 9.