Allied commanders regard the capture of Basra, along with its docks at the head of the Gulf and two airfields, as extremely important to the invasion, said the Telegraph.

The amphibious force being assembled for the task is likely to be at least 40,000 strong, the daily said, adding that the 5,500 Royal Marines will fight alongside two expeditionary units of the U.S. marines.

The attack will involve the naval task force which sails to the Gulf early next month, led by the aircraft carrier Ark Royal after its conversion into a commando assault ship.

Four Royal Navy mine-hunters, which are already in the Gulf on exercise, have been asked by the Americans to lead mine-clearing operations in the northern Gulf and to open the important Shatt al-Arab waterway leading to Basra and the Euphrates river system.

"The Americans have asked for the Royal Marines and we will send them," a senior official confirmed.

According to the paper, Britain's naval contribution will involve more than 20 ships from the Navy and Fleet Auxiliary, led by Ark Royal and the helicopter carrier Ocean.

They will soon undergo intensive training against biological and chemical attack, directed by specialists from the Ministry of Defense's chemical warfare research centre at Porton Down.

After a period of exercises, including practice landings in either the Mediterranean or the Gulf, they are expected to be ready for action by the end of January 2003, the Telegraph said.

Preparations for action are being stepped up after signs that America has set its sights on February to begin the war on Iraq - soon after the January 27 deadline for Hans Blix, the United Nations' chief weapons inspector, to report to the Security Council on Iraqi cooperation.

The other main British contributions to the war are expected to be a small armored division, RAF bombers, surveillance and refueling aircraft, and special forces, which the Americans rate as the best in NATO.

Some elements of the SAS and Special Boat Squadron are probably already in the region, it added.

Their main priority is to prevent any attack on Israel by Scud missiles from mobile launchers in the western deserts of Iraq.

The SAS and SBS will also be searching for secret command bunkers and mobile biological warfare laboratories, which have allegedly been identified to American and British intelligence by Iraqi defectors.

By the beginning of February, the Americans will be expected to have between 250,000 and 300,000 ground troops in the region - including four armored and armored-infantry divisions together with the 82nd Airborne and the 101 Air Cavalry Division.

The war will be launched with a ferocious air assault designed to achieve the total annihilation of Iraq forces within a month.

Planes from a large fleet of U.S. carriers positioned in the Gulf will launch hundreds of sorties a day against Iraqi targets.

British jets based in Kuwait, Saudi Arabia, Turkey and from the Ark Royal carrier group will also take part, the paper said.

Advances in technology mean that each of the U.S. carriers - the 86,000-ton Kitty Hawk, Harry S Truman, Abraham Lincoln and the soon-to-arrive Constellation - will be able to hit up to 700 targets a day, compared to no more than 162 in the 1991 Gulf war.

The air war will be preceded by an attack involving the use of thousands of cruise missiles being fired from British and U.S. ships and nuclear-powered submarines.

They will have as their targets air defense installations and command and control centers, effectively rendering Iraqi forces defenseless from air attack and unable to communicate with their high command.

British, and probably Dutch and Italian, fighter-bombers led by RAF GR4 Tornados from Bahrain will attack local military targets round Basra.

By then the Americans will have up to four aircraft carriers in the Gulf and Arabian Sea with 348 strike aircraft involved.

A fifth carrier, Kitty Hawk, converted to a commando and special forces platform, will lead the amphibious fleet, including the British.

The attack will be free flowing - with less of the rigid phasing of Desert Storm and Desert Sabre of 1991.

The ‘allies’ will attack in the south to take Basra, encourage rebellion among the Kurds in the north, where the British have been training local militia, and conduct commando sabotage raids throughout the country.

An all-out attack on Baghdad will be mounted only as a last resort because it is hoped that the Iraq regime will have collapsed well before this becomes necessary, the daily said.

The ‘allies’ appear to be reserving the option of having to finish the job after August, when the weather becomes cooler and ground operations are more feasible.

For this reason British Prime Minister Tony Blair is offering a smaller ground force than the one that fought for Kuwait 11 years ago, a small division, or what the Army calls a "brigade battle group".

For planners and commanders in all three services, the process of going to war has begun.