WASHINGTON, Dec 6 (Reuters) - The White House said on Saturday talks with the Democratic congressional leadership on aid to U.S. automakers would continue this weekend and participants agreed Detroit must have a plan for viability before obtaining government funds.

"We've had very constructive discussions, but there's nothing to announce yet. Talks will continue this weekend,"
White House spokesman Tony Fratto said.

Congressional Democrats and the White House reached agreement on Friday night on a price tag, between $15 billion and $17 billion, and a funding source for temporary aid, two senior congressional aides said.

The financing issues had been the primary stumbling blocks to a broader bailout agreement in recent weeks.

The money will come from a yet to be tapped Energy Department loan program approved in September to help
automakers make more fuel-efficient vehicles.

Fratto declined comment on details of the ongoing discussions.

"What's most important is that everyone now agrees that automakers must have a credible plan for viability if we're
going to consider taxpayer assistance," he said.

The Bush administration has insisted throughout the bailout debate in Washington that General Motors Corp, Ford Motor Co, and Chrysler LLC demonstrate as a condition for help that they can restructure and compete.

Both GM and Chrysler have warned of possible collapse unless each receives billions in government aid by the end of December.

Ford does not need cash now, but has asked for a line of credit in case its situation worsens in 2009.

Lawmakers were warned this week in congressional testimony that failure by one or more of the Detroit Three would have a disastrous consequence for the U.S. economy, which is in recession.