Ukraine's former Prime Minister Yulia Tymoshenko has gone on an indefinite hunger strike to demand that the Ukrainian leadership sign the Association Agreement with the European Union.

"As a sign of unity with you I am announcing an indefinite hunger strike to demand that [Ukrainian President Viktor] Yanukovych sign the Association Agreement," Tymoshenko said in a letter, read out by her defense counsel Serhiy Vlasenko on European Square in Kyiv on Monday, where a rally for European Ukraine is being held.