On 10 February 2012, she resigned from the government, citing objections with the terms of the second EU-IMF bailout for Greece.

On 1 November 2012, she resigned her membership of PASOK, expressing her objections on the new austerity measures adopted by the Greek coalition government, stating that the party no longer represented her "ideologically and politically".

In 1986, she began working as a scientific associate of the PASOK Parliamentary Group at the European Parliament.

From 2002 to the March 2004 elections, she served as Secretary General for Commerce at the Development Ministry in Greece.

In this position, she worked for the support of small and medium enterprises (SMEs), the transparency in market prices, the incorporation of commerce into European programmes, the modernisation of the legal framework of street markets, and the strengthening of consumer protection.

She had the responsibility of preparing the European Council meetings on behalf of the Greek government and followed the Institutional Issues of the E.U., the Enlargement Policy, E.U.

law in the Greek legal system as well as the representation of Greece at the European Court of Justice.

Mariliza Xenogiannakopoulou resigned from the government on 10 February 2012, citing objections with the terms of the second EU-IMF bailout, notably concerning the provisions on collective bargaining and social rights, voted against it in the Parliament (12 -2-2012) and was expelled from the parliamentary group of PASOK.

On 1 November 2012, she resigned her membership of PASOK, expressing her objections on the new austerity measures and stating that the party no longer represented her "ideologically and politically".