WASHINGTON, Sept 30 (Reuters) - U.S. Senate Democrats late on Monday rejected a last-ditch proposal by House of Representatives Republicans to establish a negotiating panel to work out a deal on an emergency spending bill and quickly end a looming government shutdown.

Senate Majority Leader Harry Reid said he would not enter such a negotiation "with a gun to our head" as government funding was running out in less than one hour. Reid called on Republicans to instead pass a Senate-approved measure that would keep the government funded through Nov. 15.

While a government shutdown now seemed inevitable, some House Republicans were predicting that their leaders eventually will relent and allow a straight-forward extension of federal funding without add-ons, such as changes to Obamacare.