Senate Majority Leader Harry Reid and other top Democrats are putting new pressure on the White House to circumvent Congress to boost the nation’s debt ceiling if no bipartisan agreement can be reached.

In a strongly worded letter to President Barack Obama obtained by POLITICO, Reid and his leadership team argue that failing to raise the $16.4 trillion debt ceiling would threaten the full faith and credit of the United States. Reid and Sens. Dick Durbin, Chuck Schumer and Patty Murray asserted that Obama “must make clear that you will never allow our nation’s economy and reputation to be held hostage.”

“In the event that Republicans make good on their threat by failing to act, or by moving unilaterally to pass a debt limit extension only as part of an unbalanced or unreasonable legislation, we believe you must be willing to take any lawful steps to ensure that America does not break its promises and trigger a global economic crisis — without congressional approval, if necessary,” the Friday letter to Obama says.

The letter amounts to the most concerted push yet by Senate Democratic leaders for the White House to take unprecedented action to raise the debt ceiling given the bitter stalemate in Congress. After the messy debt ceiling fight from 2011, and the protracted fiscal cliff battle that extended until New Year’s Day, Obama has said he will not use the debt ceiling increase as a bargaining chip and will refuse to negotiate with GOP leaders on the issue.