With GOP leadership still coming up short on a crucial deal to repeal Obamacare, more money is being considered to beef up high-risk pools used by people with pre-existing conditions, one lawmaker says.

Rep. Tom MacArthur, R-N.J., said talks have been held to add more money for high-risk pools, but he didn't specify how much. The potential change comes as some Republicans have recoiled from the bill because of concerns that it would erase protections for people with pre-existing conditions.

The potential addition comes as GOP leadership is running out of time to get a vote this week. Lawmakers have a week-long recess next week.

Rep. Mark Meadows, R-N.C., the leader of the conservative Freedom Caucus, told reporters that if the bill doesn't get passed this week then maybe it is time to move to another plan.

"I think at this point it either passes by Thursday or we have to find a Plan B or C," he said.

MacArthur also told reporters that this week is pivotal to getting the bill passed.

"If it is not done this week it will be difficult to do it afterwards," he said.

MacArthur authored the amendment to the American Health Care Act, which would partially repeal Obamacare, that lets states opt out of key Obamacare insurance requirements such as a mandate called "community rating." That forces insurers to charge an age group the same rate and prevents them from charging sicker people more.

So while people with pre-existing conditions are still guaranteed coverage, they could be charged more if they live in a state that opts out of that requirement.

But Republicans who support the legislation have pointed to federal high-risk pools and other provisions to emphasize that people with pre-existing conditions will still be protected.

While MacArthur said that there has been discussion about increasing the money given to the pools, he said it isn't a good way to reach the 217 votes needed for passage.

"I don't think you can just spend our way to getting more votes," he said Tuesday. "I think people have to get their minds around what this bill fundamentally does. The bill in multiple ways protects people with pre-existing conditions."

The legislation currently allocates $15 billion for high-risk pools in a separate amendment. And states can use whatever is left over from a $115 billion fund to stabilize the individual market for high-risk pools.

MacArthur believes that the funding is enough since the waiver for community rating would affect only a small number of people.

"It's a large enough amount of money to get this moving," he said.

But House GOP leadership is facing a perilously close vote on the bill and lost a major ally in Rep. Fred Upton, R-Mich., who came out against it on Tuesday because of concerns about pre-existing conditions.

The concern is that any major changes to the bill to lure centrists could cost support from conservatives. The MacArthur amendment was able to get virtually all of the House Freedom Caucus on board.

Meadows said he hasn't heard of any changes to the bill.

"At this point I don't see any policy changes," he said.