Andrew Banks, 28, has been jailed for two weeks after being pictured urinating next to a memorial dedicated to Pc Keith Palmer during a far-right protest in London.
Banks, of Manor Road in Stansted, Essex, was captured on camera as violent clashes between far-right protesters and police took place in central London.
Wearing a white T-shirt and grey Adidas jogging bottoms, Banks admitted one count of outraging public decency at Westminster Magistrates’ Court on Monday.
Prosecutor Michael Mallon said the Tottenham Hotspur fan was in central London to “protect statues”, but Banks did not know which statues.
He was said to have drunk 16 pints during Friday night into Saturday morning, and had not been to sleep.
Banks contacted police after being confronted by his father, the court heard.
His counsel Stuart Harris said his client was “ashamed by his action”, and had mental health issues.
Banks’s actions were widely condemned by politicians including MP Tobias Ellwood, who gave first aid to Pc Palmer as he lay dying after being stabbed to death in the grounds of Parliament by armed extremist Khalid Masood on March 22 2017.
Saturday’s far-right demonstration took place after thousands of anti-racism protesters marched in multiple events sparked by the death of George Floyd at the hands of white police officers in the US last month.
Mr Floyd’s killing has prompted weeks of discussion and outrage about racism and colonialism in the UK.
Those attending Saturday’s far-right demonstration claimed to be guarding the statue of Winston Churchill as well as the Cenotaph.
However, the event turned violent after hundreds of self-proclaimed “statue defenders” took over areas near the Houses of Parliament and Trafalgar Square and hurled missiles, smoke grenades, glass bottles and flares at police officers.
A total of 113 people were arrested and the protest was condemned by Boris Johnson as “racist thuggery” and described as “mindless hooliganism” by police.