After meeting Mikheil Saakashvili he served as one of the main figures in newly founded United National Movement and was actively campaigning against president Eduard Shevardnadze.
After moving to the opposition, he started active campaigning against President Saakashvili and at a certain point publicly accused him of cheating on his wife.
Davitashvili left his seat in Parliament of Georgia to take part in local elections to join Tbilisi City Assembly.
Shortly after finishing of the elections, footage was released which allegedly showing Davitashvili taking bribe and selling seats in his party.
The same day 2007 demonstrations in Tbilisi were dispersed by riot police, Davitashvili was severely beaten reportedly by the members of governmental forces.