Chevron’s oil leak off the coast of Rio de Janeiro last November was less than a thousandth of the size of the 2010 Gulf of Mexico spill, but it could still cripple the company’s Brazilian business and prompt wider regulatory changes, lawyers and government officials have said. Brazil’s largest oil workers’ union on...became the latest group to mount an attack on Chevron and its drilling contractor Transocean, filing a civil lawsuit that called for their expulsion from the country’s lucrative oilfields. A federal prosecutor in Rio is already suing the companies for $11bn in damages and last week demanded prison sentences for 17 of their employees, including 31 years in jail for the head of Chevron’s Brazilian operations, George Buck. In the words of the companies and even some Brazilian politicians, the accusations are “excessive” and “without merit”...“There is a concern over what happened with Chevron because of what it represents, what it can teach us,” Senator Rodrigo Rollemberg, head of Brazil’s senate environment committee...[said]“Brazil has a huge potential as an oil producer and it is important to show, both internally and to the rest of the world, that we plan to do this with the utmost responsibility.”...Marisa Dietrich, an environmental lawyer in São Paulo, said Chevron’s leak would likely turn up the pressure on the government to act and finally implement a law passed in 2000, forcing companies to invest more in contingency plans and preventative measures. [also refers to BP]