Two South Sudanese pastors in Sudan will face trial for espionage and their lawyer has been arrested.

A judge ruled on July 2 that Rev Yat Michael and Rev David Yein Reith's trial will continue, meaning that they could face the death penalty or life imprisonment if found guilty. A day earlier, July 1, their chief counsel - Mohaned Mustafa - was also arrested, along with Pastor Hafez of the Khartoum Bahri Evangelical Church where Michael spoke out against the persecution of Christians in Sudan.

According to the American Centre for Law and Justice (ACLJ), the church is involved in an ongoing land dispute with the government, and Hafez and Mustafa are accused of obstructing a public servant during the course of his duty. They have been released on bail, but will face trial in court.

Michael was arrested on 14 December 2014, and Reith in January of this year. They were both detained without charges, and without access to a lawyer or their families, until March 1. They are now being held on six charges including espionage, "offending Islamic beliefs" and undermining the constitutional system.

The men maintain they have not committed any crime. Michael recently told CBN news from his prison cell that he didn't know why he had been arrested: "We just go to to out ministry training in our church".

Their next hearing has been scheduled for July 14, and Mustafa will only be allowed about 15 minutes with his clients to brief them ahead of the meeting. "Sudanese law grants sole discretion for visitation rights at the prison to the prison directorate, who in this case has previously denied requests for access," said the ACLJ.

The pastors have also been denied regular visits from relatives, which is illegal under the Sudanese constitution. "This is meant to put more psychological pressures and warfare on the arrested pastors," a legal representative told World Watch Monitor.

"The serious criminal charges against Michael and Yen have been levied solely on the basis of their religious convictions and outspoken criticism of the ruling party, and as such, that their continued detention and criminal proceedings are discriminatory and in violation of constitutional and international legal guarantees of equality," a statement from the African Centre for Justice and Peace Studies said.

"There is also speculation that the trial of the two men is intended to send a message to other Christian leaders in Sudan to refrain from criticising the treatment of Christian minorities in Sudan and the policies of the ruling party".

Mervyn Thomas, Chief Executive of Christian Solidarity Worldwide said, "We are disappointed to learn that the judge has decided to uphold the extreme and unwarranted charges against Rev Michael and Rev Reith. We continue to call for their immediate and unconditional release. The ongoing restrictions on their legal and family visits are not only distressing for the pastors and their families, but also constitute yet another hurdle for their legal team to overcome and a violation of fair trial principles, as articulated by Article 14 of the International Covenant on Civil and Political Rights, to which Sudan is a party.

"Moreover, the harassment and assault on Pastor Hafez is wholly unacceptable, and typifies an ongoing, discriminatory policy targeting religious and ethnic minorities that is officially sanctioned. The international community, and in particular the African Union, must impress upon Sudan its obligation to protect and promote freedom of religion or belief and the right to a fair trial."