Rep. Charlie Rangel, facing a serious primary challenge next month, today picked up the endorsement of New York Mayor Michael Bloomberg (I) and former New York Mayor and Rep. Ed Koch (D).

“I’m proud to join with Ed Koch and so many others in endorsing Charlie Rangel,” Bloomberg said in a statement released by the veteran Democrat’s campaign. “For more than four decades, he has delivered for New York City time and time again. We’ve had six very different Mayors during his tenure in Congress, but we all shared one thing in common: when the City needs results in Washington, you pick up the phone and call Congressman Rangel.”

“I have worked with Charlie Rangel since 1963,” Koch said in a statement. “He served the country heroically in the Korean War and he has served New York City very well in Congress. He needs our help, let’s do it!”

Koch served in Congress from 1969 to 1977 and as mayor from 1978 until 1989.

Rangel’s most serious challenge in the June 26 multicandidate primary comes from state Sen. Adriano Espaillat. The two have been locked in an ongoing endorsement war, but getting the backing of Bloomberg and Koch will be tough for Espaillat to match.

The Harlem-anchored 13th district is safely Democratic turf, so Republicans don’t have a shot here in November.