MANILA - Graft-tainted ex-presidents, a dictator's unrepentant wife and politicians charged with crimes such as murder and child rape are among the candidates in the Philippines' mid-term elections on Monday.

The Philippines has long endured a corrupt and violent brand of democracy in which politicians use their influence to avoid punishment for crimes, creating a so-called "culture of impunity" that enrages the masses.

Below are details on 10 politicians contesting the elections who are accused of corruption or criminal activities:

1. Imelda Marcos -- 83-year-old widow of former dictator Ferdinand Marcos, who was deposed in a "people power revolution" in 1986. The first couple was accused of plundering billions of dollars from state coffers and overseeing vast human rights abuses. Running for a second term as a member of the House of Representatives as her family makes a political comeback.

2. Joseph Estrada -- Ex-president kicked out of office halfway through his six-year term in 2001 amid a popular uprising triggered by allegations he was corrupt. Convicted in 2007 of plunder while in office, but quickly pardoned by his successor. Now 76, he is running for mayor of the capital city of Manila.

3. Gloria Arroyo -- Succeeded Estrada in 2001 and served as president for nearly a decade. Her successor and current president, Benigno Aquino, has made her his top target in a war on corruption, and had multiple charges laid against her. Aged 66, she is seeking a second term as congresswoman in her home province of Pampanga while on trial and detained at a military hospital.

4. Ryan Luna -- Running for a second term as mayor of Bangued, the capital of a northern province, as an opposition candidate. Went into hiding last month shortly after being indicted for the murder of a local political rival's wife in 2007 elections. Appeared in a YouTube video denying the murder charge.

5. Rodrigo Duterte -- Veteran politician known as "The Punisher" for his tough stance against crime. Rights groups accuse him of encouraging vigilante groups that summarily execute petty criminals, including children. Running for another term as mayor of the major southern city of Davao as an independent but allied to Aquino's Liberal Party.

6. Ronald Singson -- A scion of a prominent political family in the northern Philippines, he was sentenced three years ago to 14 months in jail in Hong Kong for cocaine possession. He is seeking to regain his seat in the House of Representative that he vacated after the conviction. He is running in a province that for decades has been controlled by his father, Chavit, an admitted illegal gambling kingpin.

7. Clara "Fems" Reyes -- Wife of Joel Reyes, the former governor of the island province of Palawan. He is accused of masterminding the murder of an environment activist in 2011. She is running for mayor of a Palawan town for the ruling Liberal Party while her husband and brother-in-law are on the run after being charged over the murders.

8. Jose Rodriguez -- Running unopposed as mayor of San Marcelino town, 100 kilometers (60 miles) northwest of Manila. Rodriguez is on trial for the alleged rape of a 12-year-old girl in 2010. He is an independent candidate allied with the national opposition alliance. He denies the charges.

9. Cipriano Violago -- Running for mayor under the ruling Liberal Party for San Rafael town, 40 kilometers (25 miles) north of the capital. Went underground last week after a judge issued an arrest warrant for him for allegedly killing a policeman. He denies the charge, according to an aide.

10. Johaira Midtimbang Ampatuan -- Mayor of Datu Hoffer town in the southern Philippines, running for a second term representing the nation's main opposition alliance. She is the wife of Zaldy Ampatuan, one of the alleged masterminds of the Philippines' worst political massacre, the killing of 58 people in 2009. The massacre was allegedly an attempt to prevent a rival's election challenge. Zaldy Ampatuan, four of his brothers and their father, as well as several other relatives, are in jail while on trial for the murders.