Phoenix Vice Mayor Kate Gallego and Rep. Ruben Gallego to divorce

One of Arizona's rising political power couples is splitting up.

Phoenix Vice Mayor Kate Gallego announced on Facebook on Wednesday that the process to end her marriage to U.S. Congressman Ruben Gallego, D-Phoenix, has started.

Kate Gallego, who is pregnant with the couple's first child, did not elaborate the reason for the divorce. The couple were married in 2010.

"It is painful when any marriage ends, and it is not something that I ever wanted or expected," she wrote on Facebook. "Although we are both public officials, we consider this a completely private matter and neither Ruben nor I will be answering further questions. Instead, I will focus every ounce of energy I have preparing for the birth of our son in January and being the best possible mother I can for him."

On his Facebook page, Ruben Gallego posted, "I'm sad to announce that my marriage is ending. Kate and I hope to keep this a private matter and appreciate your respect for our privacy."

Ruben Gallego, a veteran, has represented Arizona's 7th congressional district since 2015 and easily won re-election to a second term this year. He has gained national attention for his work on veterans issues and outspoken comments about president-elect Donald Trump.

Kate Gallego has represented District 8, which encompasses southeast Phoenix and parts of downtown, on the City Council since 2014. She also led a campaign to successfully pass a tax initiative to fund transportation projects in the city.