Last week, as Securities and Exchange Commission Chairman Mary L. Schapiro was on the hot seat trying to protect her agency from potential budget cuts, she released a report by a consulting firm bolstering her plea for more money.

Now, two of the SEC’s congressional overseers are trying to determine whether the report was written independently and impartially or shaped by the SEC to advance the agency’s agenda.

In a March 15 letter to Schapiro, the lawmakers asked her to disclose “what editorial input, if any, the SEC had on the contents” of the report by Boston Consulting Group.

The lawmakers asked Schapiro to assure them “that the final report was not subjected to substantive editorial review, deletions or insertions by the SEC.” They also sought copies of earlier drafts.

The request was sent by Reps. Spencer Bachus (R-Ala.), chairman of the Financial Services Committee, and Randy Neugebauer (R-Tex.), chairman of that panel’s subcommittee on oversight and investigations.

SEC spokesman John Nester declined to comment.

Boston Consulting Group spokesman David Fondiller declined to comment in any detail on the editorial process.

“We stand by the integrity and independence of our report,” he said.

The report, a wide-ranging study of the agency prepared at a cost of $4.8 million, was ordered by Congress last year as part of its response to the financial crisis. The SEC posted it on its Web site March 10, the same day Schapiro was grilled by another House panel over her handling of a potential conflict of interest involving the agency’s response to the Bernard Madoff Ponzi scheme.

The final version differed in some ways from an earlier draft obtained by The Washington Post. For example, a suggestion that the SEC step up its oversight of an industry group that Schapiro formerly headed was softened.

In an interview Thursday, Neugebauer, who has challenged Schapiro’s plea for a budget increase, said he did “not really” have any reason to doubt the report’s impartiality. He said the request was part of a broader effort to examine studies meant to influence policy.

“This is probably not the first one of these letters that we’ll send,” he said.