Following are profiles of the country's four main political parties and their leaders:
It launched a struggle for equal rights and opportunities for people in Urdu-speaking West and Bengali-speaking East Pakistan. The struggle ultimately culminated in a movement for independence that the Bengali nationalists in Pakistan's eastern wing won in December 1971, following a war helped by India.
Its leader is Sheikh Hasina, 61, the daughter of Bangladesh's founding father and first president, Sheikh Mujibur Rahman, who was killed in an army coup in 1975 along with most of his family. Hasina has put aside her father's socialist economic ideas and gradually adopted market-orientated policies.
She became Prime Minister in 1996, defeating arch rival Begum Khaleda Zia, but lost to her nemesis in the 2001 elections. She survived an attempt on her life by Islamist militants in August 2004 when grenade blasts killed 23 people at a Dhaka rally.
Arrested in an anti-graft drive by the interim government in July 2007, Hasina was freed on medical parole after spending a year in jail. She is married to a nuclear physicist and has two children.
BANGLADESH NATIONALIST PARTY
The BNP of Begum Khaleda Zia was founded in 1978 by her late husband, President General Ziaur Rahman, with nationalism, Muslim religious values and open market policies as its motto.
After president Zia was killed in an abortive 1981 coup, Khaleda Zia took over the BNP's leadership and became the country's first woman prime minister after winning a 1991 election. The BNP lost to the Awami League in 1996 but Khaleda Zia regained power in 2001.
Khaleda Zia, 63, ended her second five-year term as prime minister in October 2006. Along with her two sons, she was arrested in the anti-corruption drive in September 2007 but was released on bail after a year in prison.
The Jatiya Party was founded in 1985 by former military ruler Lieutenant-General Hossain Mohammad Ershad, who took power in a bloodless coup in 1982.
Ershad resigned as army chief and was elected president in a controversial election in 1986, and declared Bangladesh an Islamic state. But he did not implement Islamic values or statutes rigidly, allowing all to practice their own religion.
Ershad, 78, ruled Bangladesh until December 1990 before being ousted in a "people's revolt" led by Hasina and Khaleda Zia. Ershad later launched his own political vehicle, the Jatiya Party. The party is an alliance partner of the Awami League.
Bangladesh's Jamaat-e-Islami party was formerly a branch of the Jamaat-e-Islami in Pakistan. It is accused of helping the Pakistani army during Bangladesh's 1971 war of independence -- which it denies.
Jamaat was banned in Bangladesh immediately after independence but the BNP later legalised it, allowing the party to participate in elections. It became an ally of the BNP in the 1991 election and a partner in Khaleda's coalition government in 2001 and is now the country's biggest Islamic political party.
Its leader is Matiur Rahman Nizami, 65. He was a minister in Khaleda's 2001-2006 government. Nizami was detained on graft accusations earlier this year but was released on bail a few days later.
Jamaat is allied again with the BNP and hopes to use its Islamic credentials to win support from the impoverished masses.