Iyad Allawi has said that his mainly Sunni-backed Iraqiya bloc could end its month-long boycott of parliament if Nouri al-Maliki, Iraq's prime minister, respects the power-sharing agreement between the major forces in the country.
"Once we see positive steps taken by the government to reduce the tension, to embark on dialogue and to revert back to the agreement of power sharing, then of course we will reciprocate," he told Al Jazeera.
Last month, Maliki's predominantly Shia-backed government issued an arrest warrant against Tariq al-Hashemi, the Sunni vice-president, charging that he ran death squads that targeted Shia officials.
In protest, Iraqiya, began boycotting parliament and cabinet sessions. On Tuesday, the remaining cabinet ministers suspended the members until they ended their boycott.
Hashemi denied the charges and fled to the autonomous Kurdish region in northern Iraq, out of reach of authorities in Baghdad.
He has refused to return to face trial in Baghdad, the capital.
'Arrests and intimidation'
Allawi, who served as prime minister in the government the US formed after toppling Saddam Hussein in 2003, accused Maliki of unfairly targeting Sunni officials and said the power-sharing agreement had not been honoured.
"The Iraqiya constituencies have been targeted - widespread arrests, torture, intimidation, expulsions - and then this moved into targeting the leaders of Iraqiya accusing them in the media of doing wrong things," he told Al Jazeera.
"Iraq is at a crossroads and I say that Iraq needs forgiving leaders, who will raise above their personal hatred."
- Iyad Allawi
"We saw no movements along the lines of implementing the power sharing and then these intimidations started.
"We agreed to attend the national conference to find a way out of the mess that Iraq is in."
Political rivals have agreed to hold a national conference, under the patronage of President Jalal Talabani, to resolve disputes.
The current government was formed after months of political bargaining after an inconclusive parliamentary election in March 2010.
Allawi said Iraq needed a new prime minister or new elections to prevent the country from disintegrating.
"Iraq is at a crossroads and I say that Iraq needs forgiving leaders, who will raise above their personal hatred," Allawi told a news conference in Baghdad, accusing the government of stoking sectarian tensions to divert attention from its failures.
"This is not the country that we fought the dictatorship for ... [and] not the democracy and freedom that we made sacrifices for."
Iraqi authorities said on Thursday that they had arrested a politician belonging to the party of Hashemi.
Riyadh al-Adhadh, deputy chief of Baghdad's provincial council, was arrested while on his way to work on Wednesday in connection with funding anti-government groups, officials said.
"An insurgent group confessed that he is funding them and giving them orders," a Baghdad security official told the AFP news agency on condition of anonymity.
Adhadh is a member of the Iraqi Islamic Party (IIP), a Sunni grouping that belongs to the broader Iraqiya coalition. Hashemi is a former leader of the IIP but has since split from the party.
The IIP confirmed the arrest, condemneding it as "an unprecedented escalation" and called for Adhadh to be freed.