When discussing the party’s plans with congressional Republicans this week, Vice President-elect Mike Pence, left, gave no specific direction on whether he or Donald Trump believes lawmakers should have an immediate replacement ready or how long the transition should be. | Getty

A growing number of Senate Republicans are resisting the idea of repealing Obamacare without a concrete replacement proposal, complicating GOP plans to move swiftly to undo the health care law.

Sen. Rand Paul (R-Ky.) started the open, intra-party dissension this week when the libertarian-leaning senator urged Republicans to vote on a replacement plan at the same time they pass a repeal bill. He was followed a day later by hard-line conservative Sen. Tom Cotton (R-Ark.), then by the more centrist Sen. Bob Corker (Tenn.).

And Paul said on Twitter late Friday that the most important Republican, President-elect Donald Trump, is fully on board, too.

“I just spoke to @realDonaldTrump and he fully supports my plan to replace Obamacare the same day we repeal it,” Paul wrote. “The time to act is now.”

At least a half-dozen GOP senators have now expressed public or private concerns about the party’s current trajectory. Their worry: Republicans will be blamed for wreaking havoc on the health care system and causing people to lose their coverage without any assurance they have a superior — or any — plan of their own.

“I think the president-elect’s position is the right position,” Corker told reporters on Friday morning. “During the campaign he said that repeal and replace should take place simultaneously. That to me is the prudent course of action.”

The GOP can only lose two votes in the narrowly-divided Senate once Mike Pence becomes vice president and can break a tie. The package is expected to include a related provision to defund Planned Parenthood, which makes it more difficult for a pair of moderate Republicans, Sens. Susan Collins of Maine and Lisa Murkowski of Alaska, to support it.

People close to Senate Republican leadership believe that they’ll ultimately have the votes to get the repeal plan through. Republican lawmakers, they say, will be hard-pressed to vote against killing a law so widely despised by conservatives.

But the complaints among lawmakers from various wings of the party are clouding the outlook.

“We’re going to have to work out the differences and try to build consensus to get it done. To me it’s unfathomable that we would not come up with the 51 votes. So we have to figure out where that sweet spot is,” said Senate Majority Whip John Cornyn (R-Texas). “I just don’t think failure is an option.”

Pence discussed the party’s repeal-and-delay plans with House and Senate Republicans this…