In the House, a minority wing of conservative Republicans long tormented Speakers Boehner and Ryan from the right. Now, a new crop is threatening fellow partisans in the Senate in a similar manner. 

Republicans and Democrats in the upper chamber have unveiled a bipartisan budget bill for fiscal year 2023. Conservatives in the House are saying they will spend the next two years fighting Senate Republicans on everything should they pass this budget before the GOP takes control of the House in two weeks. 

In a letter sent to the GOP Senate caucus, 13 House members threatened to fight “even the smallest legislative and policy efforts” by any senator who votes for the funding bill. “We are obliged to inform you that if any omnibus passes in the remaining days of this Congress, we will oppose and whip opposition to any legislative priorities of those senators that vote for this bill — including the Republican leader,” the letter said. 

Congressman Chip Roy, a House Freedom Caucus member and author of the letter, said that Senate Republicans are undermining their party’s ability to negotiate with the Biden administration. “It is the willingness of Senate Republicans to abandon for now the one leverage point we have — the power of the purse — to stop Biden’s purposeful refusal to secure and defend our borders that is most offensive,” the letter read. 

Leader Kevin McCarthy — in a rare moment of harmony with more conservative House members — agreed with the letter’s authors. “When I’m Speaker, their bills will be dead on arrival in the House if this nearly $2 [trillion] monstrosity is allowed to move forward,” Mr. McCarthy said in a tweet. 

According to a press release from the Senate Appropriations Committee, the legislation — which totals $1.7 trillion — includes a 5.5 percent increase for domestic spending programs. “We can either do our jobs and fund the government, or we can abandon our responsibilities without a real path forward,” Senator Leahy wrote. 

Senator Shelby, the top Republican on the Appropriations Committee, hailed the deal as a victory for our national defense. “I’m pleased that this package meets the level set by the NDAA last week, which is $76 billion over last year — an increase of 10%,” Mr. Shelby said in a statement. The bill also includes $40 billion for military and humanitarian aid for Ukraine. 

Conservatives in the House have said support for that besieged country should be curtailed in the new Congress. Congresswoman Marjorie Taylor Greene said before the midterms that “not another penny will go to Ukraine.” Congressman Michael McCaul, set to be the chairman of the Foreign Affairs Committee, said the days of “blank checks” are over under the GOP. 

Conservative members like Senators Hawley and Rubio have been working on the budget, signaling there could be a wide margin of passage on the final vote. Senator Hawley worked with Democrats to include a provision that bans the social media platform TikTok from government-owned electronic devices. 

Messrs. Shelby and Leahy, who are both retiring in two weeks, have taken a serious bite out of the House GOP’s power. In 2023, Mr. McCarthy as speaker would have only two points of leverage with the White House — government funding and the debt ceiling. With this deal likely to pass, Mr. McCarthy would lose a significant amount of power in his first year on the job.