TONY Blair today signalled the start of a bloody battle for Baghdad, as Allied aircraft pounded units of Saddam Hussein's elite Republican Guard.

Speaking at a Downing Street press conference, the Prime Minister confirmed coalition troops were now just 50 miles outside the Iraqi capital city.

He said: "Be under no doubt, the purpose is to remove the regime, and to do that it is important to move to Baghdad."

Advance units of the coalition force have been pounding military targets with rockets and howitzers from near Karbala, about 80 kilometres (50 miles) south of Baghdad.

Mr Blair confirmed troops were meeting stiff resistance from the Republican Guard, which remains loyal to Saddam Hussein.

A defiant Mr Blair said: "There will be resistance all the way to the end of this campaign. At the same time, there will be the continuing skills and dedication and professionalism of our Armed Forces to break this down.

"Let nobody, least of all the forces loyal to Saddam be in any doubt this resistance will be broken down and the goals of the coalition forces will be met."

Mr Blair said he could understand why Iraqi civilians had shown reluctance at the arrival of coalition forces.

He understood they had been left disappointed when Saddam was not toppled during the 1991 Gulf War. But he assured them this time "we will not let you down".

Mr Blair also confirmed he would fly to Washington after Prime Minister's Questions in the Commons at 12 noon tomorrow (wed) to hold a council of war with President Bush.

He will also discuss humanitarian aid and how to build an alliance with Europe to reconstruct post-war Iraq.

Mr Blair will also meet UN general secretary Kofi Annan in New York in a bid to mend bridges after Britain and the US waged war without a second resolution.

The bombardment of the Republican Guard on the southern approaches to Baghdad marked a new phase in the war.

Aircraft have flown more than 900 sorties in the last 24 hours as part of a plan to soften up Baghdad's defenders and try to prevent them retreating into the city itself.

Air strikes targeted the Medina Division, considered to be one of the best and most powerful elements of the Republican Guard.

Mr Blair said the encounter with the Medina Division on the ground would be a "crucial moment".