The Awami League, led by Sheikh Hasina, holds 58 seats in the 300-seat assembly and walked out last January claiming that the parliament speaker was not granting its politicians enough time to speak during debates.
Were they to prolong their boycott beyond 14 February then Hasina and her colleagues would have lost their parliamentary membership, which dissolves automatically after 90 consecutive business days of absence.
On Saturday said: "Now we have decided to go back to bargain people's demands as we don't want to give the government and ruling Bangladesh Nationalist Party a chance to ignore them any more."
However, some observers were sceptical as to whether Hasina would stay in parliament any longer than the time needed to save her membership, saying she has already threatened to quit again unless her demands are met.
The Awami League wants the government immediately to reform the country's election commission, including sacking the chief election commissioner who it says is favouring the government, and also bring some changes to the system of caretaker government which oversees national polls.
Abu Ahmed, professor of economics at the Dhaka University, said: "We hope the Awami League will play a vital role in parliament to help the country overcome its challenges.
"They should not only try to protect their memberships."
Bangladesh, a predominantly Muslim country, has been rocked by a wave of bomb blasts by Islamist militants that have killed at least 30 people and wounded 150 since August.
Hasina is expected to lead her party back into parliament for the first time on Sunday evening.
But they will miss direct debate with the prime minister, Begum Khaleda Zia, who is due to leave earlier for a three-day visit to Pakistan.