Gerry Adams has claimed his arrest has galvanised his party’s European election campaign.
The Sinn Fein president, 65, was released from Antrim police station a week ago after four days of questioning by detectives about the 1972 murder of Belfast mother-of-10 Jean McConville and other alleged links with the IRA.
The former West Belfast MP has vehemently rejected allegations made by former republican colleagues that he ordered her abduction and death, and after his release described his arrest as a “sham”.
He said: “It has galvanised the Sinn Fein party and the broader republican family.
“Now they are very focused, there is an alertness that the process here cannot be taken for granted and people are looking to the work that Martin (McGuinness) and our other representatives have done around raising peace process issues.”
Mrs McConville, a 37-year-old widow, was dragged, screaming, away from her children in the Divis flats in west Belfast by a gang of up to 12 men and women after being wrongly accused of informing to the security forces.
She was interrogated, shot in the back of the head and then secretly buried - becoming one of the “Disappeared” victims of the Troubles. Her body was not found until 2003 on a beach in Co Louth, 50 miles from her home.
Mr Adams’ arrest prompted deputy first minister Mr McGuinness to claim that a “dark side” at the Police Service of Northern Ireland (PSNI) was behind his detention, an allegation chief constable Matt Baggott has denied.
Mr Adams said his arrest had not been beneficial to him or his family after 20 years of the peace process.
He added: “The worst thing is the signal that it was sending out to citizenry that have vested and invested their hopes in the future.
“I would like to think that the calming of the waters afterwards was down to the diligence and comments of our leadership.”
Mr Adams was speaking at an election manifesto launch in Belfast.
Sinn Fein claimed that the party leader’s arrest was orchestrated by an old guard of officers intent on damaging the party before the elections.
This was angrily rejected by political rivals, whose fury intensified when Sinn Fein indicated that its support for the police - a critical plank in the peace process - would be “reviewed” if Mr Adams was charged.
The veteran republican has been canvassing in Cork in the Irish Republic since his release.
He said: “I have found that people voting for us welcome the fact that I am out. It is a nice experience to have strangers stop me on the street.”
Five-party talks on unresolved peace process issues were chaired by former US diplomat Richard Haass around Christmas but broke up without agreement.
Aims included the creation of a new framework for deciding on the route of contentious parades, when to fly the Union flag from official buildings, and dealing with the impact of 30 years of violence on victims and their families. One proposal included qualified immunity for perpetrators in exchange for information about Troubles killings.
Sinn Fein signed up but the blueprint was not accepted by unionists.
Mr Adams said: “The issues need resolved. The important thing to note is the British Government have not signed up to Haass.
“If a British Government leaves unionist leaderships room to manoeuvre and wriggle, then they will manoeuvre and wriggle and that is what we have seen.”
He said the Irish Government needed to face up to its responsibilities as co-guarantor of the 1998 Good Friday Agreement, which largely ended violence.
Irish deputy prime minister or Tanaiste Eamon Gilmore has said there is a window of time between the end of the elections and the start of the marching season in which progress could be made and added “there may well be a role for him (Dr Haass) again”.
Mr Adams is a former West Belfast MP and now a member of Ireland’s Dail (parliament) for the border constituency of Louth.
He said Dr Haass and his deputy put forward compromise proposals drawn from wider civic society.
“The unionists need to face up to it. These issues are not going to go away and the British Government needs to face up to it as well.”
Sinn Fein European election candidate Martina Anderson criticised her leader’s arrest.
“People have seen that this was an attack on the peace process and an attack on democracy.
“The arrest of our leader, as Gerry said, has galvanised our activists across the north and island but has also brought into sharp focus the attention of the wider nationalist/republican population with regards to the importance of this peace process.”