A House conservative group formerly chaired by Vice President Mike Pence plans to issue their healthcare demands to Republican senators amid growing reports that the bill has moved further to the left.

The 151-member Republican Study Committee is sending a letter to Senate Majority Leader Mitch McConnell, R-Ky., detailing what the group's members want to see in a bill repealing and replacing Obamacare, raising new questions about whether Republicans will be able to come together to pass the legislation.

Republican Study Committee members say in the draft letter they would like to see many conservative policies in the House-passed American Health Care Act preserved in whatever Obamacare bill emerges from the Senate.

This includes phasing out Medicaid expansion beginning in 2020. They also want to keep the repeal of all taxes under Obamacare, an area where Republicans broadly agree but raises questions about how to fund the healthcare law.

House conservatives also want to block federal family planning funds for cancer screening, testing and birth control from going toward medical facilities that also perform abortions and ban tax credits from going toward health insurance plans that cover abortions. There are questions over whether the latter provision would be allowed under the Senate's procedural rules and centrist Republicans object to cutting off federal funding from Planned Parenthood.

The Republican Study Committee continues to support a controversial amendment that would allow some states to apply for waivers to opt out of insurance mandates, including the obligation for insurers to cover a range of medical benefits, and for them to charge people who are the same age the same amount for coverage regardless of their healthcare status. Centrists in both the House and Senate have raised concerns about these waivers because they worry that they would make insurance prohibitively expensive for people with pre-existing illnesses, an outcome was projected by the Congressional Budget Office.

"As the Senate continues its deliberative process, we urge you to carefully evaluate the American Health Care Act and consider the important role these specific policies played in building consensus in the House," the Study Committee wrote.

Few people have seen the bill, but some media interviews with lawmakers have left conservatives concerned about the details. Republicans are attempting to reconcile the competing priorities among their members, some of whom worry about the cost of premiums and healthcare and others who worry about their constituents losing coverage.

One of the possibilities that has emerged from Senate talks is that its healthcare bill not phase out Medicaid expansion for seven years. Under Obamacare, states can use federal funds to expand the provision to cover low-income people.

Senate GOP leaders have set a deadline to repeal portions of Obamacare ahead of the Fourth of July, but deep divisions remain over these provisions, and the bill's approval rating is low. Republicans are advancing their healthcare bill through a budget measure known as reconciliation, which relies on a simple majority for passage. Still, the Republican-controlled Senate can afford to lose no more than 50 votes, assuming a tie-breaking vote by Vice President Pence, to guarantee passage.