EXCLUSIVE: A top Republican senator is raising questions about how an agency official at the center of a high-stakes power struggle with the White House landed her job, claiming her application was “hastily approved” as part of “a flawed vetting process” shortly after President Trump’s election.

Sen. Ron Johnson, R-Wis., head of the Senate Homeland Security Committee, is now asking the U.S. Office of Special Counsel to investigate Leandra English’s move to “burrow” into a “career position” at the Consumer Financial Protection Bureau – switching from a political post at another agency in a shift that may have helped her stay employed in the government. “Burrowing” is a term used to describe political appointees shifting to career positions.

In a Thursday letter obtained by Fox News, Johnson alleged that English got her job based on information that included “errors” and “potential conflicts of interest.”

“[I]t may be appropriate for the Office of Special Counsel to review whether the conversion of Ms. English from a political appointment at OPM to a career position within CFPB adhered to the merit system principles,” Johnson wrote to U.S. Special Counsel Henry Kerner.

English was the deputy director tapped last November by outgoing Obama appointee Richard Cordray to replace him at helm of the bureau, an Elizabeth Warren-touted agency which Republicans have accused of over-regulating lenders and operating with little oversight. Within hours, Trump named White House budget director Mick Mulvaney as acting bureau director. This prompted a lawsuit by English which a federal judge effectively dismissed, saying that denying a president the authority to make his own pick “raises significant constitutional questions.”

To this day, English remains as deputy director, serving under Mulvaney.

But the day after the judge’s Nov. 27 ruling, Johnson sent a letter to the U.S. Office of Personnel Management asking about English’s switch to the CFPB in late 2016, apparently after Trump was elected and before he took office. He asked how the agency allowed English – previously “a political appointee at OPM during the Obama administration” -- to “burrow” into a career position at the CFPB.

“I am concerned that [her] conversion into a career position was abused for political purposes,” Johnson wrote at the time in a letter to OPM acting Director Kathleen McGettigan.

'I am concerned that [her] conversion into a career position was abused for political purposes.' — Sen. Ron Johnson, in November 2017 letter

In the fresh letter sent this week to Kerner, Johnson noted that McGettigan, in her response to the senator’s November inquiry, said English’s conversion was “free from political influence.”

However, he also said that McGettigan, in her response letter, verified by Fox News, exposed “a flawed vetting process” in English’s job switch.

Johnson said the response shows CFBP presented to OPM English’s application for a conversion “nearly three months after the position posting closed.” He also says OPM “hastily vetted and approved” the conversion -- taking just 14 working days for the final approval.

Johnson also argued that OPM originally reported that English’s change came with an $11,000 salary increase. But the agency only corrected that figure – to $43,000 – in late December, blaming “clerical errors.” This was well after the change had been approved.

He also raised questions about a conflict of interest, given that English worked for an official whose internal move created the vacancy and who served on the interview panels that resulted in her selection.

The CFPB did not immediately return a request for comment. The Office of Special Counsel acknowledged receiving the letter but declined to comment. Attempts to reach English directly were unsuccessful.

The CFPB was conceived by now-Massachusetts Democratic Sen. Elizabeth Warren after the 2007-2008 financial crisis and was established by Congress several years later to protect consumers from predatory lending. Trump has called the agency a "total disaster" and installed Mulvaney to rein in and reform the agency.