Thirteen vulnerable Republicans are urging Speaker Mike Johnson to “immediately turn our focus” to extending Obamacare subsidies after the government reopens.

The group, led by GOP Reps. Jen Kiggans of Virginia and Jeff Van Drew of New Jersey, laid out its case Tuesday in a new letter to Johnson, reminding him that millions of Americans face skyrocketing health insurance premiums as a result of the expiration of the subsidies at the end of the year.

While the moderate members acknowledge Republicans must not cede to Democratic demands that the subsidies be extended during the shutdown, they also emphasize that Johnson must help the party “chart a conservative path” forward on the credits immediately after the shutdown ends.

“Allowing these tax credits to lapse without a clear path forward would risk real harm to those we represent,” wrote the lawmakers. “Our Conference and President Trump have been clear that we will not take healthcare away from families who depend on it.”

Conversations have already started around pairing an extension of the enhanced Affordable Care Act tax credits with conservative health care policy priorities. There are discussions about making changes to the structure of the tax credits themselves, for instance instituting new minimum out-of-pocket premiums for all enrollees and imposing an income cap for eligibility.

House GOP leaders are engaged in early, informal conversations with White House officials about potential changes, too. Still, many hard-liners remain dug in against any extension, which Republicans across the political spectrum caution would be a political mistake heading into the midterms.

The Republicans said in their letter that they agree with their conservative colleagues that changes are needed: “Let us be clear: significant reforms are needed to make these credits more fiscally responsible and ensure they are going to the Americans who need them most.”

But with no resolution in sight to the 21-day government funding standoff between the two parties, the letter signals mounting GOP anxiety about the issue as Nov. 1 fast approaches. That’s the date for open enrollment in plans under the Affordable Care Act, at which point it might be too late to avoid massive premium hikes.

State insurance officials have warned that an expectation that the enhanced tax credits will expire has already been baked into updated insurance rates, and it will be difficult to update those rates if Congress passes an extension in November or December.

Kiggans introduced a bill in September that would extend the subsidies for a year, which currently has the support of 28 co-sponsors, equally divided between the two parties. Twelve of the signers of the Johnson letter are supporters of the Kiggans measure.