A Congressman has expressed shock after a pride flag was ripped down from outside his office.

Rep. Alan Lowenthal of California revealed that an unnamed man threw the rainbow flag outside his Capitol Hill offices.

Mr Lowenthal is a strong advocate for LGBT rights and a supporter of the Equality Act, which Democrats recently re-introduced.

However yesterday a man ripped the LGBT-supporting flag down and stomped on it, calling it “disgusting and immoral”.

“The fact that someone would grab a flag that they didn’t like and not just throw it on the ground, but stomp all over it… it’s certainly shocking,” Lowenthal, who is vice chair of the House LGBT Caucus, told the L.A. Times.

Despite the angered attack on the flag, police said they could not charge him with any crimes, as the act was not illegal.

He was released shortly after questioning.

The Long Beach representative has been a strong supporter of LGBT rights, erecting the flag back in 2013, and is thought to be the only congressional representative to have done so.

Reacting to the incident, he added: “I just think it’s terrible. I’m just shocked that it happened. It just reinforces my belief that more work needs to be done.”

Congressional colleagues have spoken out about the incident – expressing indignance at what happened.

Nancy Pelosi wrote: “#LGBT pride flag is a symbol of equality & freedom. The attack on ?️‍? at @RepLowenthal’s office is an attack on our values as a nation.”

While fellow California representative Jackie Speier posted: “Disturbed & outraged by hateful attack on @RepLowenthal’s #PrideFlag – We can’t allow bigoted behavior to become the new normal #werewithyou”

Meanwhile ex-congresswoman Michele Backmann has called on Trump to revers the ‘evil’ gay agenda.