As President George W. Bush struggles against Congressional opposition to a strategy to increase U.S. forces in Iraq, a top ally has moved in the opposite direction by offering a drawdown schedule for its forces.

Prime Minister Tony Blair is set to announce a new conditions-based plan to make it possible to bring 1,500 British troops home from Iraq in the next several weeks during his weekly address before the House of Commons Wednesday morning, FOX News confirmed.

Bush, who spoke with Blair about the issue via video link this morning, called the proposed cuts a "sign of success" in a statement released by the White House. Blair said Sunday that Washington had not put pressure on London to maintain its troop numbers.

Blair will also say that pending security conditions in southern Iraq, where most U.K. forces are stationed, a total of about 3,000 British soldiers will have left by the end of 2007, according to unidentified government officials quoted in a BBC report. Britain hopes to reduce its 7,200-member force in the southern city of Basra to approximately 5,500 by May, FOX News has learned.

British forces would maintain the same combat capacity and have healthy troop strength to address any emerging security threats, Blair's expected to say.

FOX News obtained some of the key points Blair is expected to make on Wednesday.

— Reshaping U.K. deployments on the ground so as to maximize our contribution to the prospects for successful transition.

— Over the coming months, we intend to consolidate our bases in the Basra area. In some cases that will mean handing those bases we no longer need to the Iraqi authorities.

— This will have the benefit of reducing the number of British troops needed for static guarding. It will free up a greater proportion of troops for training and mentoring work with the Iraqi Police, Army and Border Guards

— It will also serve as a visible demonstration to Basrawis of our commitment to sustainable transition.

— Overall, the changes we plan to our force posture will allow us to reduce our current commitment in Iraq from 6 to 5 Battle Groups by the time the next major rotation of troops is completed in May.

— That will mean a reduction from the 7,200 British troops deployed today to some 5,500 ——-This is a substantial UK force that will remain in Iraq — reflecting our continuing commitment to the future of that country, and the importance of the challenges that remain before us

—It is by no means a withdrawal of U.K. troops from southern Iraq. Nor indeed will it represent a reduction in the effect we will be able to deliver. We will keep the same combat capability as we have now.

— The changes will see Iraqi units doing more of the regular patrolling of Basra's streets, and UK troops less. But we will retain a robust re-intervention capacity. Our capability to respond to any emerging security problems or support the ISF will be undiminished.

— We will of course keep a close eye on progress and on the implications for our force levels. It may be possible to make further adjustments later in the year."

U.S. National Security spokesman Gordon Johndroe released a statement saying the president was pleased that the British contingent in the Basra area has been able to stabilize conditions to the point where more security responsibilities can be shifted to Iraqi troops.

"The president is grateful for the support of the British forces in the past and into the future," said Johndroe in Washington. "While the United Kingdom is maintaining a robust force in southern Iraq, we're pleased that conditions in Basra have improved sufficiently that they are able to transition more control to the Iraqis.

"The United States shares the same goal of turning responsibility over to the Iraqi security forces and reducing the number of American troops in Iraq," Johndroe said. "President Bush sees this as a sign of success and what is possible for us once we help the Iraqis deal with the sectarian violence in Baghdad."

"We want to bring our troops homes as well," Johndroe said. "It's the model we want to emulate, to turn over more responsibilities to Iraqis and bring our troops home. That's the goal and always has been."

Bush's plan to implement a surge of 21,000 additional troops for Iraq was condemned by a nonbinding resolution passed by the House and a similar measure that was defeated in the Senate last week.

As recently as late last month, Blair rejected opposition calls to withdrawal British troops by October, calling such a plan irresponsible.

"That would send the most disastrous signal to the people that we are fighting in Iraq. It's a policy that, whatever its superficial attractions may be, is actually deeply irresponsible," Blair said on Jan. 24 in the House of Commons.

Blair, who has said he will step down as prime minister by September after a decade in power, has seen his foreign-policy record overshadowed by his role as Bush's leading ally in the unpopular war.

The Associated Press contributed to this report.