Massachusetts Rep. Barney Frank, Congress' first member to voluntarily announce he's gay, has said redistricting was behind his decision to retire.

The 71-year-old Frank said at a news conference on Monday that he would not seek re-election in 2012 because of redistricting changes that would force him out of his 4th Congressional District and into an attempt to represent new constituents for only a few years before he retires.

“This decision was precipitated by Congressional redistricting,” he said, adding that there are “other things I'd like to do in my life before it's over.”

He said that he plans to remain active in politics.

“I look forward to being able to help change the system,” Frank said. “I will miss this job and I will have some twinges of regret before the new Congress is signed up, but one of the advantages of this is I will no longer have to be nice to people I do not like.”

Frank officially came out gay at the age of 47, during his fourth term as congressman, in a Boston Globe May 30, 1987 front page story titled Frank Discuses Being Gay. He said he was prompted to come forward by the death of Stewart McKinney, a closeted bisexual Republican representative from Connecticut.

The House formally reprimanded Frank in 1990 over allegations made by a male prostitute, Stephen Gobie.

Frank said he believed coming out had an impact.

I believe it had an impact,” Frank said. “The best antidote to prejudice is reality. Because prejudice is by definition based on ignorance of people's real condition.”