House Speaker John A. Boehner's proposal for a six-week extension of the debt limit fell flat in the Senate Thursday evening, where members of both parties were clamoring to end the government shutdown, now in its 11th day.

As the House prepared to vote on Boehner's proposal Friday, Senate Minority Leader Mitch McConnell (R-Ky.) was holding meetings with his rank and file to develop a competing proposal to re-open the government and raise the federal debt limit for as long as three months.

The package was being assembled by Sen. Susan Collins (R-Me.) and has attracted the interest of Senate Democrats, sparking the first bipartisan negotiations since the stand-off began in early September.

“I was surprised that the House decided to deal only with the debt limit and not with the continued closure of government,” Collins said Thursday. “I think that we have to deal with both issues and we need to do so quickly.”

Senate Democrats were intrigued by Collins’ proposal, but unhappy with its demand for Democratic concessions. Those include repeal of a tax on medical devices needed to fund the new health care initiative and new income verification procedures for people who receive tax subsidies to buy health insurance on the law’s new exchanges.

In addition, Collins’ proposal would maintain deep cuts known as the sequester through  at least March. Though it would grant agencies flexibility to decide where the cuts would fall, the sequester remains a red flag for the White House and many Democrats, who want to restore funding for domestic programs.