Rubuta ci gaba don wannan sakin layi - Tattaunawa don gyara hukumomin EU sun fara ne a shekara ta 2001, wanda ya fara haifar da yarjejeniyar da aka tsara don kafa Tsarin Mulki na Turai, wanda zai soke yarjejeniyar Turai na yanzu kuma ya maye gurbin su da "kundin tsarin mulki". Kodayake yawancin ƙasashe membobin sun amince da shi, an yi watsi da shi bayan an ƙi shi da kashi 55% na masu jefa ƙuri'a na Faransa a ranar 29 ga Mayu 2005 sannan kuma da kashi 61% na masu jefa ƙuri'a na Dutch a ranar 1 ga Yuni 2005. Bayan "lokacin tunani", kasashe membobin sun amince maimakon haka don kiyaye yarjejeniyoyin da ke akwai da kuma gyara su, don kawo doka da dama daga cikin gyare-gyaren da aka tsara a cikin tsarin mulkin da aka watsar. An shirya yarjejeniyar "gyare-gyare" mai gyarawa kuma an sanya hannu a Lisbon a 2007. Da farko an yi niyyar cewa dukkan kasashe membobin za su amince da shi a karshen shekara ta 2008. Wannan jadawalin bai yi nasara ba, musamman saboda ƙin amincewa da Yarjejeniyar a watan Yunin 2008 ta masu jefa ƙuri'a na Irish, shawarar da aka juya a cikin kuri'ar raba gardama ta biyu.
a watan Oktoba 2009 bayan da Ireland ta samu wasu abubuwan da suka shafi yarjejeniyar.