Several religious groups of various professions are hoping that a last-ditch effort on Wednesday to stop the passage of a controversial gay-rights law that could result in discrimination against religions will work.

Several Christian groups will hold a prayer vigil outside Parliament tomorrow morning to coincide with the Lords debate of the Sexual Orientation Regulations, reported The Telegraph.

Christian, Jewish, and Muslim leaders have criticized the new bill, arguing that that it would "discriminate heavily" against anyone who expresses the view that gay sexual acts are not equal to the conjugal love of heterosexual married couples.

The Catholic bishops have said that the regulations could force the closure of their 13 adoption agencies, which will lose government funding if they refuse to place children with same-sex couples.

Baroness O'Cathain will propose a motion against the regulations when they come before the House of Lords on Wednesday. Her motion notes “the widespread concerns that the draft regulations compromise religious liberty and will result in litigation over the content of classroom teaching.”

However, Cardinal Cormac Murphy-O’Connor said the debate on Wednesday is not enough considering the social importance of the issue. “Profound public concern about aspects of these Regulations has not been heard.  The debate on Wednesday in the House of Lords, although important in itself, will hardly compensate for the lack of a full debate in the House of Commons,” he said in a statement issued on behalf of the bishops’ conference of England and Wales.

The cardinal expressed the bishops’ concern about the impact of the regulations on the “cooperation between faith-based voluntary agencies and public authorities in public funded services.”

“The truth is these new laws will prevent Christians acting in accordance with their conscience, whether they are running an adoption agency or a business," Andrea Williams, spokeswoman for the Lawyer's Christian Fellowship, told The Telegraph.

"Vulnerable people will suffer. And, most worrying of all, Ministers have admitted that the laws will apply to the delivery of education in schools,” she was quoted as saying.

"This suggests that teachers in schools (whether faith based or not) will no longer be able to teach established Christian doctrine about marriage and relationships for fear of being sued by gay rights campaigners," she reportedly said.

A House of Commons committee approved the regulations last week, but the procedure was heavily criticized by all the main parties because the government gave the 16 members just 17 hours notice of the hearing.

“It is, surely, an abuse of Parliamentary democracy that these regulations are being considered by Parliament only through a hurriedly arranged and very brief meeting of 16 appointed MPs, and a short debate in the House of Lords,” the cardinal also criticized. “During the House of Commons Committee meeting opportunity for serious debate was denied.”