>>3:10 p.m. EDT: The motion passed with Vice President Mike Pence casting a vote to break the tie.

The Senate is expected to hold a vote Tuesday on a motion to proceed to debate the House version of the health care bill.

The vote, a procedural one, is the first step in a Republican effort to repeal and replace the Affordable Care Act.

(See live updates below)

Here’s what you need to know about the bill and the vote expected for Tuesday afternoon.

What time is the vote?

The vote is expected around 2:30 p.m. ET. It is set for after Republican senators meet for their weekly lunch. The lunch begins at 12:45 p.m.

What are they voting on?

The vote is on a motion to proceed with debate on the House health care bill.

What happens if the motion passes?

If the procedural motion passes, debate, along with an amendment process would begin. The amendment process would allow an amendment that agrees with budget reconciliation rules.

What happens if the motion fails?

Never say never in Washington. If the vote fails, the Senate may move on to tax reform or could take another stab at the bill, negotiating with the GOP senators who have opposed various parts of the legislation.

Is there a Republican who is solid on a no vote?

Maine Sen. Susan Collins says she will not vote on the motion to proceed.

Anyone on the fence about voting yes?

These Republican senators have expressed doubt on the bill.

Sen. Shelley Moore Capito

Sen. Dean Heller

Sen. Ron Johnson

Sen. Mike Lee

Sen. Jerry Moran

Sen. Lisa Murkowski

Sen. Rand Paul

Sen. Rob Portman

What are the chances it passes?

Probably pretty good or you wouldn’t see two things that are happening today: One, there likely wouldn’t be a vote if GOP leaders didn’t feel they would win, and, two, Sen. John McCain, (R-Arizona) is returning to Washington in time to cast a vote. McCain was diagnosed with an aggressive type of brain cancer a couple of weeks ago. It would be unlikely he would come back to Washington to vote on a bill that party leaders don’t feel will pass.

How many votes will it take to pass?

Senate Majority Leader Mitch McConnell can lose only two Republican senators and see the motion pass. That is assuming that every Democrat votes no on the motion. There are 52 Republican senators. If two of them vote no, the bill can still pass with the help of Vice President Mike Pence. The vice president is the tie-breaker if a vote in the Senate ends up in a tie.

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