In 1988 he was named Director General of the Penitentiary Institutions under Justice Minister Enrique Múgica Herzog.

To establish the policy which tried to break ETA prisoner discipline he also worked with the leader of the Basque Nationalist Party, Xabier Arzalluz.

[1][2] In the 1993 general elections Asunción obtained a seat in the Congress of Deputies for the Electoral District of Valencia, he would serve until 1996.

When Roldán fled the country Asunción, having been in office for five months, offered his resignation to González, who refused.

[4] The PSOE suspended his membership in 2011, stating that Asunción made numerous allegations of electoral fraud without evidence.

[6] In June 2015 Asunción was indicted by judge Santiago Pedraz [es] of the Audiencia Nacional, he was charged with fraudulent bookkeeping and criminal conversion in a case concerning the sale of his share in the company Acuigroup Maremar to the Banco de Valencia.