Lib Dem spokeswoman Baroness Sharp of Guildford complained about the speed at which it was being rushed through but supported it as a "stop-gap measure".
The "Barnett Floor" would provide a stop-gap measure to address the fact that the gap between spending in Wales and spending in England can diminish over time.
Should Congress vote and fail to pass a bill, Obama also says he will instruct Senate Majority Leader Harry Reid, a Democrat, to introduce a stop-gap measure in an up-or-down vote.
Consulting with the agency's lawyers, Mr. Donahoe started late last year to look at how the language of the stop-gap measure currently funding federal government operations might free the Postal Service to end Saturday service.
Sanchez said he expects that ultimately a deal will get done before the deadline, or a small stop-gap measure will be agreed to in order to buy more time, which would cause gold prices to retreat.