Mexico City, Mexico - Only one day after the Mexican Senate passed the controversial legislation to open the state-controlled oil sector to foreign investment, it was also approved by the Chamber of Deputies, or the lower house of Congress.

The new energy law allows private oil and gas companies to drill for oil and gas with the state-run firm Pemex in exchange for a share of the profits.

Opposition lawmakers protested vigorously against the bill, saying the new legislation would damage the national interests of Mexico, and there were scuffles during the long debate in the lower house of the Mexican Congress.

Landy Berzunza of the governing PRI party was taken to hospital with a scratched retina after an altercation with opposition representative Karen Quiroga. Another opposition congressman, Antonio Garcia Conejo, stripped down to his underwear to show his rejection of the bill.

President Enrique Pena Nieto says private investment is needed to modernize the energy sector and boost falling oil production.

Lawmakers use chairs to barricade the main chamber

Historic Bill

Private firms will be allowed for the first time since 1938, when the sector was nationalized, to explore and extract oil and gas with state-run firm Pemex - and to share the profits.

The Chamber of Deputies voted 354 to 134 to give general approval to the bill, but throughout the debate, members of the opposition Democratic Revolution Party, or PRD, tried to disrupt the proceedings to prevent the passage of the bill. Some occupied the podium in the main chamber, others barricaded the chamber's entrances to prevent Deputies from the PRI, PAN, and Nueva Alianza parties, who backed the reform, from entering.

The debate was moved to an alternative venue, where it got even more heated.

'Ruffians'

Left-wing lawmaker Ricardo Monreal took to the podium with a thermos can, saying it was a time capsule in which he would put the names of the "traitors of the fatherland" who had voted for the reform bill.

Mr. Garcia Conejo of the PRD, while taking his jacket, tie and shirt off, said the governing party was robbing Mexico of its assets, calling it a "plunder of the nation."

"This is how you're stripping the nation. Where is the benefit? I'm not ashamed, what you're doing is a shame!" he said as he dropped his trousers and removed his socks.

Shouts of "ruffians" and "traitors" could be heard throughout the debate, while some lawmakers made obscene gestures at others who had interrupted them.

Members of the governing PRI party said the bill was crucial to drive Mexico's economy forward and to better exploit Mexico's oil riches. Oil production in Mexico has dropped from 3.4 million barrels per day in 2004 to the current rate of 2.5 million barrels per day.

The bill is key to President Enrique Pena Nieto's drive to reform the Mexican economy.

The bill still needs to be approved by 17 of Mexico's 32 federal entities - the District Federal and 31 states.