By Steve Holland

WASHINGTON, Sept 5 (Reuters) - President Donald Trump on Tuesday is expected to rescind a program shielding from deportation some immigrants who came to the United States illegally as children, throwing their fate to Congress, which would have six months to find a fix.

Sources familiar with the matter, who spoke on condition of anonymity to outline the president's thinking ahead of the announcement, stressed that the decision was not final and that Trump could change his mind at the last minute.

The expected decision, with U.S. Attorney General Jeff Sessions scheduled to hold a briefing at the Justice Department on Tuesday, would amount to a six-month extension of the Deferred Action for Childhood Arrivals, or DACA program, to give Congress time to devise an alternative.

DACA, created by Democratic President Barack Obama in 2012 after Congress failed to pass legislation that would have created a pathway for citizenship for undocumented youth, protects nearly 800,000 young men and women, often called "Dreamers," from deportation and allows them to work in the United States legally. The group is a small fraction of the estimated 11 million illegal immigrants in the United States.

Under the envisioned Trump policy shift, Dreamers with valid work permits would be able to stay in the United States until their permits - which are issued for two-year periods - expired, the sources said. At the same time, the Department of Homeland Security would not target Dreamers for deportation, according to one of the sources.

The move is an attempt by Trump to find a middle ground between Democrats who want the president to leave the Obama-era policy alone and conservatives who consider DACA a form of amnesty for illegal immigrants.

As a result, the president is likely to draw fire from both sides.

Nine Republican state attorneys general have said they would sue if Trump does not act to end the program, while a number of Democratic state attorneys general have threatened action if he does.

While Trump talked tough on DACA during his presidential campaign, he has publicly expressed a reluctance to deport Dreamers since taking office.

"We love Dreamers. We love everybody," Trump said on Friday.

The sources said Trump's six-month extension is aimed at pressuring Congress to protect the Dreamers through legislation. There is a widespread belief in the Trump administration that the Obama DACA policy would not withstand legal challenges from the Republican attorneys general, who argue Obama overstepped his bounds in creating the program.