Senators on Tuesday left town for the rest of the week with no plan on when to bring up a bill Republicans deemed the last shot to overhaul Obamacare.

Republican leaders are trying to pin down if they have enough votes to pass an Obamacare overhaul bill, but lawmakers recessed for the rest of the week and are expected to return Monday. The GOP is under a major time crunch because it has to pass the legislation before midnight Sept. 30, when a tool that would allow the bill to be approved with a simple majority instead of the 60 usually needed to break a filibuster expires.

Senate Majority Leader Mitch McConnell has repeatedly told the four Republican senators pursuing the bill that he will bring it up only if it has 50 votes. Vice President Mike Pence can break a 50-50 tie.

Some senators want McConnell to bring the bill up for a vote even if it doesn't have 50 yes votes. The bill would give Obamacare funding to states in the form of block grants and would eliminate the individual and employer mandates.

"The way we lose as a party is not to try," said Sen. Lindsey Graham, R-S.C., one of the bill's co-sponsors. "The only way we lose and people hate our guts right now thinking we aren't putting our full shoulder into repealing and replacing Obamacare."

However, there is another wrinkle for Republicans as they scramble for votes: the Jewish holiday of Yom Kippur, which is Sept. 30.

Graham pointed out that the Senate passed Obamacare in 2009 on Christmas Eve, which is a pretty big deal. However, he would understand if the Senate has to break to ensure lawmakers don't work on the Jewish holiday.

"I want to honor every religion's holiday, so if we have to break for the Jewish holiday we have to break for the Jewish holiday," he said. "I don't want to get on the wrong side of God."

Sen. John Cornyn, R-Texas, said all options are on the table in response to a question about bringing up the bill for a vote without solid support from 50 senators.

Senate leaders do not know how far away they are from landing 50 votes. Sen. Rand Paul of Kentucky is the only Republican to come out publicly against it.

A "skinny" Obamacare repeal bill that was to be a vehicle for talks with the House failed by a 49-51 vote in late July.

Republican Sens. John McCain of Arizona, Lisa Murkowski of Alaska and Susan Collins of Maine joined every Senate Democrat to vote against it. All of them have said they are undecided on the new legislation, although Collins has criticized the bill.

Collins has said that she wants to see what the Congressional Budget Office has to say on the legislation. The nonpartisan agency said this week it will release a preliminary estimate early next week on how the bill would affect the deficit, but it will take several weeks to determine how it would affect insurance coverage and premiums.

Several Democrats have criticized Republicans for planning to vote on the bill without a full analysis from the agency.

Other key centrists are still on the fence publicly about the legislation, including Sens. Rob Portman, R-Ohio, and Shelley Moore Capito, R-W.Va., who come from Medicaid expansion states.

The bill seeks to create funding parity between expansion and non-expansion states. It would end the Medicaid expansion in 2019, and from 2020 to 2026 it would give $1.17 trillion in block grants to states.

Non-expansion states are expected to receive more money initially from the federal government while the expansion states would get less.