Employees at the venerable Gallup polling firm suggested they felt threatened by Obama campaign adviser David Axelrod when he questioned the methodology of a mid-April poll showing Mitt Romney leading the president – according to internal emails published Thursday.

That poll showed Romney leading Obama 48-43 percent.

The exchange, according to emails published by The Daily Caller, started when Axelrod sent a tweet saying the tracking poll was “saddled with some methodological problems” and directing followers to a National Journal story in which a professor suggested outdated sampling.

According to the email chain titled “Axelrod vs. Gallup,” the White House in addition asked that a Gallup staffer “come over and explain our methodology,” which was apparently perceived as a subtle threat.

A Gallup official said in an email he thought Axelrod’s pressure “sounds a little like a Godfather situation.”

“Imagine Axel[rod] with Brando’s voice: ‘I’d like you to come over and explain your methodology…You got a nice poll there … would be a shame if anything happened to it… .’”

The exchanges also show that Gallup invited White House officials to its Washington offices, but it remains unclear whether any of the meetings occurred.

However, when Gallup declined to change its polling methodology, the Obama administration’s Justice Department revived a 2009 whistle-blower lawsuit against the firm by joining the suit, a senior Gallup official alleges.

The suit was filed by former Gallup employee Michael Lindley, who claims the firm violated the False Claims Act by overcharging the federal government for its services.

Gallup declined to talk about the issue. Calls to the Justice Department, the White House and the Obama campaign have not been returned.

Obama campaign adviser Robert Gibbs told The Washington Times this week that he was unaware of any communications between the campaign and Gallup.