Fifty-three Democratic senators have signed a letter to House Speaker John A. Boehner saying they intend to vote against his plan for an increase in the debt ceiling, virtually assuring its defeat in the Senate even as the speaker lines up Republican votes to pass it in the House on Thursday.

Votes are not final until they are cast. But if the Democrats hold to their promise in the letter, Mr. Boehner’s plan for a six-month increase in borrowing authority will not make it to President Obama’s desk.

“We heard that in your caucus you said the Senate will support your bill,” the senators say in the letter. “We are writing to tell you that we will not support it, and give you the reasons why.”

In the letter, the senators argue that a short-term extension of the debt ceiling would “put America at risk” and “could be nearly as disastrous as a default.”

Some compromise there, eh?

I say the House GOP and whatever Democrats who dare, pass the bill anyway and dare Dingy Harry to hold it up for defeat in the Senate.

To the Democrats then, you voted twice against House passed plans, so if it breaks the American economy, you own it baby – House/Senate Democrats and President Obama.

Here is the double dare letter to Boehner:

Dear Speaker Boehner,

With five days until our nation faces an unprecedented financial crisis, we need to work together to ensure that our nation does not default on our obligations for the first time in our history. We heard that in your caucus you said the Senate will support your bill. We are writing to tell you that we will not support it, and give you the reasons why.

A short-term extension like the one in your bill would put America at risk, along with every family and business in it. Your approach would force us once again to face the threat of default in five or six short months. Every day, another expert warns us that your short-term approach could be nearly as disastrous as a default and would lead to a downgrade in our credit rating. If our credit is downgraded, it would cost us billions of dollars more in interest payments on our existing debt and drive up our deficit. Even more worrisome, a downgrade would spike interest rates, making everything from mortgages, car loans and credit cards more expensive for families and businesses nationwide.

In addition to risking a downgrade and catastrophic default, we are concerned that in five or six months, the House will once again hold the economy captive and refuse to avoid another default unless we accept unbalanced, deep cuts to programs like Medicare and Social Security, without asking anything of the wealthiest Americans.

We now have only five days left to act. The entire world is watching Congress. We need to do the right thing to solve this problem. We must work together to avoid a default the responsible way – not in a way that will do America more harm than good.