She was a member of Barnet London Borough Council for Oakleigh Park Ward from 2006 to 2010 where she was chair of the Cleaner, Greener, Transport and Development Overview & Scrutiny Committee.

She led calls in the Committee on Women's Rights and Gender Equality for an impact assessment of the legislation to be conducted which resulted in the proposals being shelved.

Yannakoudakis led a campaign to ensure that EU rules do not make it more difficult for electronic cigarette users to access e-cigs.

[11] Yannakoudakis worked to support efforts to find people who went missing during the Turkish invasion of Cyprus and Cypriot intercommunal violence.

[19] Yannakoudakis was strongly opposed to the introduction of a European Union financial transaction tax[20][21][22] which she believed would have an adverse effect on the City of London.

[23] She led a cross-party multi-national campaign to secure a level playing field for sugar cane refiners, including London's Tate & Lyle where jobs are under threat.

Yannakoudakis called for Iceland to fully compensate all UK depositors, especially the London councils which had invested surplus money.