After a meeting at Pachachi's house in Baghdad on Friday attended by at least three cabinet ministers, 15 parties and political groups signed a petition saying the polls should be postponed for up to six months.
Iraq's electoral commission said it would examine the request.
"We will examine this request tomorrow morning. It's a very
complicated question," Commission Chairman Abd al-Husayn al-Hindawi said.
Meanwhile, the electoral commission has extended the deadline for parties to present their full lists of candidates for the elections, so as to allow them more time to form alliances.
"We have decided to push the deadline for registering candidates to 5 December in the provinces and 10 December in Baghdad," al-Hindawi said.
He said the decision was made "upon the request of several political figures, and in order to allow the formation of joint lists and the broadest possible participation".
To register, firstly a list name of a political entity - a party, group or individual - must be announced.
Individuals have to pay much
less than political parties
Secondly, the full nominal list of candidates running on that list must be announced once it has been approved by the commission.
The deadline for the first stage of this process was originally set for 22 November. The commission has received 232 applications.
Political entities must announce their list name, submit a logo and produce a list of 500 signatures of support.
Parties have to write a cheque for 7.5 million dinars ($5000), while individuals have to pay only a third of that amount.
As per Friday's decision, the second phase of the registration has been moved back from 23 November to 5 December in the provinces and from 30 November to 10 December in Baghdad.
The number of candidates on any list must be no lower than 12 and no higher than 275, which is the number of seats in the future national assembly.
"We have decided to push the deadline for registering candidates to 5 December in the provinces and 10 December in Baghdad"
Abd al-Husayn al-Hindawi,
A candidate must be aged at least 30 and hold a high school degree. Former members of the Baath party, which ruled under the deposed government of Saddam Hussein, must first renounce their ideology in a written statement.
The official electoral campaign will kick off on 15 December and end on 28 January, 48 hours before the vote.
Parties have spent recent weeks locked in intense talks to form alliances and try to clinch a maximum number of seats in the single, proportional ballot.