Updated

Richard Grenell, Mitt Romney's openly gay Foreign Policy and National Security spokesman, has resigned from his post after the Romney campaign allegedly silenced him.

In a statement, Grenell said:

"I have decided to resign from the Romney campaign as the Foreign Policy and National Security Spokesman. While I welcomed the challenge to confront President Obama's foreign policy failures and weak leadership on the world stage, my ability to speak clearly and forcefully on the issues has been greatly diminished by the hyper-partisan discussion of personal issues that sometimes comes from a presidential campaign. I want to thank Governor Romney for his belief in me and my abilities and his clear message to me that being openly gay was a non-issue for him and his team."

According to a source close to Grenell, his decision to resign came after the Romney campaign "put Ric on the shelf and wouldn't let him engage on anything with the media," while national security issues became the focus this past week. The source said Grenell wanted to "take the fight to Obama" over accusations by the President and his campaign that Romney would not have ordered the risky operation to take out Bin Laden last year. But the Romney campaign became too "squeamish", instead only allowing surrogates like John McCain to respond.

However, another source disputes this claim, saying the decision was amicable. Several senior staffers over the weekend reached out to Grenell,  asking him to remain with the campaign, but he declined. The source also said Grenell wasn't scheduled to start until May 1.

Romney campaign manager Matt Rhoades released a statement saying, "We are disappointed that Ric decided to resign from the campaign for his own personal reasons. We wanted him to stay because he had superior qualifications for the position he was hired to fill."

Hired less than two weeks ago as part of the Romney campaign's staff buildup ahead of the general election, Grenell brought more than a decade of foreign policy experience to the relatively inexperienced campaign. He served as the director for communications and public diplomacy at the United Nation for seven years under President George W Bush.

But his appointment didn't sit well with many anti-gay conservatives, who voiced concern in various right leaning publications over him being openly gay and supporting gay marriage. He also caused a stir when snarky tweets from his Twitter account, mostly directed at liberals and women, were brought to light.

Fox News Chief Washington Correspondent James Rosen contributed to this report.