Joan Baldoví began the striptease while he was speaking in Spain's parliament on the issue of home evictions.
As Baldoví spoke in favour of Spain's anti-eviction protestors, he first removed his jacket.
Moments later, he removed his tie, pulling it up over his head.
This was greeted by laughter and jeers before the speaker of Spain's parliament Jesús Posada told the member of parliament to behave himself.
When Baldoví began to unbutton his shirt, Posada warned: "Mr Baldoví, if you continue to behave like this, I'm going to have disallow you from speaking."
But Baldoví continued on to reveal he was wearing a red t-shirt bearing the words "Stop Desahucios".
The design of the t-shirt was identical to those used by Spain's peak anti-evictions lobby the PAH.
The PAH, led by the Barcelona-based activist Ada Colau, have received a great deal of negative press in recent times because of their so-called "escrache" protests — or demonstrations that directly target the homes and offices of politicians.
Spain's Prime Minister Mariano Rajoy has repeatedly labelled the "escraches" undemocratic while his second-in-command María Dolores de Cospedal has called them “pure Nazism”.
But Baldoví said the protestors were not "terrorists or Nazis".
He said they were "dignified people who were fighting for a just cause".
"They are people: listen to them," the deputy concluded.
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One of the most traumatic effects of this long economic recession has been the huge number of home evictions in Spain, with many people finding themselves unable to pay their mortgages.
Figures from a national judiciary council show that Spain's courts have carried out a staggering 252,826 expulsion orders since 2008, news agency AFP reported recently.
In total, 38,778 primary and secondary residences were taken back by lenders last year, said the country's El País newspaper in early April.
At the same time, a housing census carried out by Spain's national statistics office showed that 20 percent of Spanish residences stood empty in 2011.
Baldoví is no stranger to the national stage, reported the newspaper 20minutos on Wednesday.
He has repeatedly stood up to criticize the government on corruption scandals including that involving the ex-treasurer of the ruling Popular Party Luis Bárcenas.
Bárcenas is accused of administering an illegal slush fund for the party.