Lula da Silva, Brazil's first democratically elected left-wing President, continues to face criticism over an official he fired Friday after video was released showing him cutting secret deals with a lottery kingpin: "Lula is confronting the most delicate moment of his administration," the daily Jornal do Brasil warned on Sunday morning. Opposition leaders have responded to the revelations by calling for a congressional investigation and demanding the immediate resignation of José Dirceu de Oliveira e Silva, the president's chief of staff and the immediate superior of Mr. Diniz. The president of the Workers' Party, José Genoino, has tried to distance the party from the scandal and the damage it has done by arguing that Mr. Diniz is "not enrolled in the party." But newspaper reports and opposition leaders have countered by noting that Mr. Diniz not only is a former roommate and longtime political associate of Mr. Dirceu but also held one of the government's most delicate jobs, that of the executive branch's liaison to Congress. The videotape and an accompanying transcript show Mr. Diniz, then the head of the state lottery in Rio de Janeiro, agreeing to rewrite an online lottery contract so as to favor a numbers game kingpin known as "Charlie Waterfall." In return, the numbers game boss agreed to contribute more than $100,000 to the Workers' Party candidates for governor in Rio and Brasília during the 2002 general election and to pay a 1 percent "tip" to Mr. Diniz. Mr. da Silva himself has not commented directly on the new situation. But at an event in Rio on Friday night commemorating the 24th anniversary of the founding of the Workers' Party he expressed his support for Mr. Dirceu and other party leaders. "The trademark of our party is its ethical behavior and its honor," he said as angry demonstrators chanted outside.