WASHINGTON Twelve House Republicans have come out against the latest GOP-led effort to open up a 1.5 million-acre swath of Alaskas fragile Arctic National Wildlife Refuge to oil and gas development.

Included in the Senate version of the Republican tax plan is a bill, introduced by Sen. Lisa Murkowski (R-Alaska), that would require Interior Secretary Ryan Zinke to approve at least two lease sales for drilling each no fewer than 400,000 acres in the coastal plain area of the refuge. This region in northeast Alaska, also know as the 1002 Area, is home to polar bears, moose and caribou, and has been the subject of a decades-long battle between energy producers and conservationists.

In a letter Thursday to party leaders, GOP Reps. Dave Reichert (Wash.), Brian Fitzpatrick (Pa.), Ryan Costello (Pa.) and others said the refuge, better known as ANWR, stands as a symbol of our nations strong and enduring natural legacy.

Any development footprint in the refuge stands to disrupt this fragile, critically important landscape, the group wrote to House Speaker Paul Ryan (R-Wis.) and Senate Majority Leader Mitch McConnell (R-Ky.).

The letter does not specifically mention Murkowskis legislation. (In a separate statement , however, Costello urged Congress not to include changes to the refuge in the tax plan.) Rather, it highlights the decades of bipartisan support for protecting the area and notes the Trump administrations push to allow seismic testing and other activities in the coastal plain, a move the group says could threaten imperiled species and fragile habitat.

Opening the coastal plain is on the Trump administration s fossil fuel-centric wish list. In May, Zinke signed an order to jump-start Alaskan energy production. He said at the time that the move was an important first step in a smart and measured approach to energy development in ANWR. Additionally, the administrations 2018 fiscal year budget calls for allowing oil and gas production in the coastal plain.

During a hearing last month, Murkowski said shes confident drilling would not come at the expense of the environment and that she and many other Alaskans believe the coastal plain is actually one of the best places that we can go for responsible development.

Environmental groups many of which blasted a pair of Senate committees after they advanced Murkowskis bill were quick to voice support for the group of Republican lawmakers that signed the letter.

We applaud these Representatives for recognizing that protecting the Arctic Refuge from drilling matters to anyone who cares about our wild spaces no matter which side of the aisle theyre on, Mike Brune, executive director of the Sierra Club, said in a statement.

The Senate is expected to vote Friday on its tax proposal.

The Senate budget plan included a provision that required the Senate Energy and Natural Resources Committee, which Murkowski chairs, to come up with $1 billion in additional revenue over the next decade to help pay for tax reform. The Congressional Budget Office estimates the ANWR legislation would generate slightly more than $1 billion in federal revenue over the next decade a figure that has been widely disputed .