The families of Andrew Chan and Myuran Sukumaran have made an eleventh hour plea for the lives of the two men ahead of their executions this morning, after "tough and dark" hours saying their final goodbyes.

Indonesian attorney-general Muhammad Prasetyo said the executions will take place after midnight local time (3:00am AEST).

The convicted drug smugglers have entered what Indonesian officials call the "quiet period", as they count down the hours to their death by firing squad.

Earlier Indonesian security forces moved into the Cilacap port area to clear several hundred members of the public away from the ferry terminal which services Nusakambangan prison island.

More than 1,200 security officers from the police and military are involved in operations supporting this round of executions.

Just hours before the executions, Indonesian authorities reversed an earlier decision to deny Sukumaran and Chan access to their spiritual advisers before their deaths.

Indonesian security forces move into the Cilacap port area to clear members of the public away ahead of the executions. ( ABC: Greg Jennett )

Michael Chan said both his brother and Sukumaran are "dignified" ahead of the executions, which he said amount to "cruel, undignified torture".

"I saw today something that no other family should ever have to go through," he said.

"Nine families inside a prison saying goodbye to their loved ones.

"To walk out of there and say goodbye for the last time, it is torture."

Raji Sukumaran pleaded with president Joko Widodo for clemency for her son and Chan.

"I won't see my son again and they are going to take him tonight and shoot him and he is healthy and he is beautiful and he has a lot of compassion for other people," she said.

"I am asking the government not to kill him, please president, please don't kill him.

"Call off the execution."

Joining calls for clemency, Sukumaran's brother, Chintu, said the execution of the nine prisoners on Nusakambangan prison island would do little to address the drug problem in Indonesia.

"We spent the last few hours with my brother ... we did talk about the death penalty and he knows this is just a waste," he said.

"He knows this is not going to solve anything with drugs.

"I ask the president to please show mercy.

"Please don't let my mum and my sister have to bury my brother."

Michael Chan and Chintu Sukumaran make a final plea to president Joko Widodo. ( AAP: Darma Semito )

Chan and Sukumaran vow to take care of other prisoners

Despite the fate awaiting the pair, Chintu said his brother and Chan were taking care of the other prisoners due to be executed.

"Myu has told us that he is going to be strong and him and Andrew will take care of the other seven people and he is worried for Mary Jane [Veloso, another prisoner due to be executed] and her family as well," he said.

Myuran Sukumaran's sister is carried through the crowd as his family arrive in Cilacap ( ABC News )

"We still have hope right up until the last second that the president will see each of these people are individuals, as people with families that love them and show mercy."

In tears and holding on to her brother for support, Brintha Sukumaran pleaded with Mr Widodo for clemency.

"Please don't do this to my brother," she cried.

"I beg you please, please don't take my brother from me."

Family members returned from their final visit with more paintings done by Sukumaran.

One of them depicted a heart with an inscription on the back that read: "Satu hati, satu rasa di dalam cinta." (One heart, one feeling in love.)

It had been signed by all nine prisoners facing death.

A joint statement from the governments of Australia, France and the European Union pleading with Mr Widodo to halt the executions has also been made public.

"It is not too late to change your mind," the statement said.

"It is our hope that Indonesia can show forgiveness to 10 detainees.

"In filing this petition, we ask Indonesia also reflect on the impact on Indonesia's position in a globalised world and an international reputation.

"We support Indonesia's efforts to obtain forgiveness for its citizens abroad. Stopping this execution will help those efforts."

A painting of a heart by Myuran Sukumaran, which has an inscription on the back which reads satu hati, satu rasa di dalam cinta (one heart, one feeling in love). ( AAP: Roni Bintang )

Pair given access to spiritual support in final moments

The pair were initially denied their right to spiritual support from their nominated pastors Christine Buckingham and Pastor David Soper, before the decision was overturned in the hours leading up to the scheduled executions.

Indonesian law stipulates that where the death penalty is applied, condemned prisoners are allowed a religious counsellor in the final moments before they are shot by firing squad.

It is their only support in the last moments of life and the religious cleric of their choosing can also witness the death penalty being carried out.

Mr Prasetyo is expected to hold a press conference after the executions.

A group of family and friends who embarked at Cilacap for the first trip to the Nusakambangan today were mobbed by media, with Sukumaran's sister needing to be carried through as photographers pressed in.

An ambulance carrying nine coffins arrived at the ferry terminal shortly afterwards for the short trip to the island.

The painting was signed by all nine prisoners on death row on Nusakambangan island. ( AAP: Roni Bintang )

Brandis appeals for stay until court case is heard

Attorney-General George Brandis has appealed to his Indonesian counterpart to stay the executions until proceedings underway in the country's Constitutional Court and Judicial Commission have been completed.

A preliminary hearing of the Constitutional Court has been scheduled for May 12, which Senator Brandis said is relevant to the cases of Chan and Sukumaran.

"Respectfully, the Australian Government calls on the president and attorney-general of Indonesia to stay the executions until the Constitutional Court and Judicial Commission proceedings are completed," Senator Brandis said.

"It would be a terrible outcome if rulings or findings in either of these proceedings called into question executions which have already been implemented and are irrevocable."

Coffins have been brought to the port at Cilacap, in preparation for the executions. ( ABC News: Greg Jennett )

A lawyer for two men, Peter Morrissey, said the investigation would only be useful if Chan and Sukumaran were able to take part.

A candlelight vigil was held outside the Indonesian Embassy in Canberra. ( Nick Haggarty )

"You don't kill the prisoners while there's still a court case that could affect their lives," he said.

More than 200 people gathered in Sydney's Martin Place to call for the cancellation of the executions, while gatherings were also held in cities around the country including Adelaide, Canberra, Brisbane and Melbourne.

Among the speakers at the Sydney vigil was renowned international human rights lawyer Geoffrey Robertson who told the crowd the men would not die in vain.

"Australia and other countries will make it less likely that others suffer their fate, suffer their torture that they've had to go through," he said.