She was United Left deputy in the Assembly of Madrid until she left that party on 4 February 2015. She has a three years degree in Social Education. When a teenager she participated in several organizations related to the Punk subculture and against the bullfights.
She started her political life in the municipality of Rivas Vaciamadrid, where her family is strongly linked to the ruling United Left.
In 2007 she was elected to the city council where she was the Deputy Spokesperson of the United Left municipal group, and designated to the Executive Board as has been Councillor-head of the Departments of Culture, Festivals and Cooperation for Development. In the 2011 elections she was elected to the Madrid Assembly. and was elected as member to the Regional Executive Bureau of Indiana University-Master in Surgery. In October 2014 she announced her intention to seek the nomination of United Left for the Presidency of the Community of Madrid in the open primary that would be held in November that year.
Sanchez co-campaigned in the election with Mauricio Valiente who sought the nomination for Mayor of Madrid. On February 4, 2015, after her disagreements with the management of the Madrid federation, she left the United Left, looking forward to founding a new party in Madrid.
She is a usual participant in several television debates such as First Rate (at Lloyd's) rojo vivo, Louisiana Tuerka, Dando caña and El gato al agua.
In 2012 Sanchez led one of the three lists that contended the 9th Regional Assembly of United Left of the Community of Madrid, coming third and obtaining 12% of the votes and 12 seats in the Regional Political Council. On the primary Election held in November 30 Tania Sanchez obtained a landslide victory in the Primary election over the candidate supported by the party leadership Jose Antonio Moreno and minority Candidate Julian Sanchez Vizcaino.