Republicans are seeking to undermine the Government Accountability Office as it investigates, and considers suing, over the Trump administration’s withholding federal funds.

A federal watchdog has opened dozens of investigations to determine if President Trump and his top aides have illegally withheld billions of dollars in congressionally approved funds.

Now, Republican lawmakers are working alongside the White House to stymie those inquiries and the officials conducting them, in a move that could help Mr. Trump seize more control over the nation’s budget.

The attacks target the Government Accountability Office, a roughly century-old agency formed to help Congress keep track of federal spending. The legislative office primarily produces detailed reports on ways that Washington can save money, sometimes rankling administrations that are not so keen about its allegations of waste.

But oversight officials have recently found themselves in a direct and highly unusual confrontation with the White House over the power of the purse. The