Critics of the church argue that no group has a constitutional right to a government contract, especially if it refuses to provide required services.

But Anthony R. Picarello Jr., general counsel and associate general secretary of the United States Conference of Catholic Bishops, disagreed. “It’s true that the church doesn’t have a First Amendment right to have a government contract,” he said, “but it does have a First Amendment right not to be excluded from a contract based on its religious beliefs.”

The controversy in Illinois began when the state legislature voted in November 2010 to legalize civil unions for same-sex couples, which the state’s Catholic bishops lobbied against. The legislation was titled “The Illinois Religious Freedom Protection and Civil Unions Act,” and Bishop Paprocki said he was given the impression that it would not affect state contracts for Catholic Charities and other religious social services.

In New York State, religious groups lobbied for specific exemption language in the same-sex marriage bill. But bishops in Illinois did not negotiate, Bishop Paprocki said.

“It would have been seen as, ‘We’re going to compromise on the principle as long as we get our exception.’ We didn’t want it to be seen as buying our support,” he said.

Catholic Charities is one of the nation’s most extensive social service networks, serving more than 10 million poor adults and children of many faiths across the country. It is made up of local affiliates that answer to local bishops and dioceses, but much of its revenue comes from the government. Catholic Charities affiliates received a total of nearly $2.9 billion a year from the government in 2010, about 62 percent of its annual revenue of $4.67 billion. Only 3 percent came from churches in the diocese (the rest came from in-kind contributions, investments, program fees and community donations).

In Illinois, Catholic Charities in five of the six state dioceses had grown dependent on foster care contracts, receiving 60 percent to 92 percent of their revenues from the state, according to affidavits by the charities’ directors. (Catholic Charities in the Archdiocese of Chicago pulled out of foster care services in 2007 because of problems with its insurance provider.)