Garda killer Pearse McAuley is due to be charged in connection with the stabbing of a former Sinn Fein councillor on Christmas Eve.
McAuley, who is aged in his 50s, is due to appear before a special sitting of Cavan District Court this evening at 5pm.
He was arrested in relation to the knife attack on his wife and was last night released from hospital into garda custody.
Former Sinn Fein councillor Pauline Tully-McAuley was stabbed several times at her home in Killnaleck, Co Cavan, on Christmas Eve but is said to be "doing well" and is expected to recover.
It is understood that the horrific attack was witnessed by the couple's two sons who are aged seven and four.
Ms Tully-McAuley's husband, who served 10 years in prison for killing Detective Garda Jerry McCabe, was also being treated in Cavan General Hospital until yesterday evening.
McAuley was apprehended by gardai while his wife was being rushed to hospital.
He was hospitalised himself for "underlying medical issues".
It is understood that he had also sustained injuries, including a broken nose, when a man came to his wife's aid.
Gardai arrested the convicted terrorist under Section 4 of the Criminal Justice Act but suspended his interrogation to allow treatment in hospital, where he was under armed guard.
Sources said his questioning was to continue after his release from hospital and that a decision would then be made whether to proffer charges.
Ms Tully-McAuley suffered up to a dozen serious stab wounds in an ordeal that lasted for three hours on Wednesday.
She managed to alert neighbours to what had happened and they called gardai and an ambulance.
A friend told the Herald that the mother of two was "doing well" and would recover.
"She will be okay. The family have gone to visit her in hospital. It looks she's going to be all right," the friend added.
Sinn Fein members are holding a number of emergency meetings to discuss the possible fallout after McAuley's arrest.
"Apart from the family tragedy involved, Sinn Fein are very concerned about all this. Pauline is a member of the party. Pearse is considered a hero of the IRA," a local party activist revealed.
"But there is a lot of anger about this and we want to see justice done.
"This was a savage attack on a mother of two little boys who has served her party well. This attack was unforgivable."
McAuley, who shot his way out of Brixton Prison in 1991, met his wife when she visited him during his time in jail for the manslaughter of Det Gda McCabe.
Sinn Fein was heavily criticised in 2009 when TD Martin Ferris arrived at Castlerea Prison to pick up McAuley and fellow gang member Kevin Walsh.
Yesterday, a senior Sinn Fein figure spoke for the first time following the attack on Ms Tully-McAuley when Cavan-Monaghan TD Caoimhghin O Caolain expressed his support and sympathy for the former party councillor.
"I have known and worked with Pauline Tully-McAuley for many years. I am proud to call her a colleague and a friend," he said.
"The horror of the ordeal that Pauline and her children faced on Christmas Eve is beyond comprehension.
"The community is greatly upset and is hopeful that Pauline makes a full recovery.
"I have spoken to a member of Pauline's family and conveyed my sympathy and support, and that of the many hundreds of fellow activists throughout the constituency."
Last year, gardai were alerted to an incident during which Ms Tully-McAuley was allegedly beaten up by her husband in a Dublin hotel.
Another guest who tried to intervene was also assaulted.
But no complaint was made, and gardai were forced to drop their investigation.