Around 50,000 demonstrators have rallied in the centre of Kiev to demand that Ukraine's government reverse course and sign a landmark trade and cooperation agreement with the European Union.
This process was started not by political parties but by the civil society and NGOs, and after political parties joined this process. But we have to understand that signing this agreement is a political choice ... is a choice between future and past ... and we understand that signing these documents with the European Union will start a great reform in Ukraine.
The Ukraine backed out of a deal, which was due to be signed with the EU on Friday, after several secret meetings with Russia. Moscow has reportedly threatened unspecified economic measures if Ukraine signs the EU deal.
The public show of force was the largest since the Orange Revolution in 2004 - during which peaceful protests brought a Western-leaning government to power.
One of the key demands of protesters and the EU is the release of former Prime Minister Yulia Tymoshenko who has become a symbol of Ukraine's troubled democracy.
Tymoshenko's daughter Eugenia was one of those attending Sunday's protest march, saying: "All I can say is that the Ukrainian people, as well as the opposition should fight and stand for our national interests, for the fulfillment of conditions by the president and to sign the agreement. The chance still exists. We hope that it will be, and that it becomes a reality."
But this time, the number of protesters has not been sustained, and the government is showing no signs of backing down.
Russia and Ukraine share much of their history, but since the fall of the Soviet Union, relations have been tense. The 1990s were marred by territorial disputes, but they signed a friendship treaty in 1997, which brought a period of improved relations.
The Orange Revolution in 2004 again raised problems. And in 2009, Russia cut off gas supplies to Ukraine in a dispute over prices, causing mid-winter fuel shortages across Europe.
Moscow also opposed Kiev's desire to become a member of NATO; the Kremlin ramped up the pressure and in October, Ukraine gave up its bid.
So how strong is the anger in Ukraine over the EU deal? What is behind the recent protests? Why has Ukraine turned back to the old Soviet fold? Will the government sign a deal with Russia? Or will people's anger force Ukraine's government into yet another reversal?
Inside Story, with presenter Laura Kyle, is joined by guests: Ostap Semerak, an adviser to the opposition Batkivshchyna group; Pavel Felgenhauer, a defence analyst and columnist for Russia's online news website, Novaya Gazeta; and Lilit Gevorgyan, a specialist on Russia and the former Soviet states for IHS Global Insight.
"I think there were a number of factors that came into play during the negotiations. First of all because both the EU and Russia have been struggling and fighting over Ukraine .... It has put Kiev in some sort of a peculiar position where it could pick and choose which policies ... would have benefited the country the most. The issue is that economically speaking Ukraine is in a dire state and it has immediate financial assistance need .... The EU has effectively said to Ukraine that they have to go through some painful macro-economic decisions to unlock this financial assistance .... In terms of the immediate gains it appears that the Russian offer was much more appealing."
Lilit Gevorgyan, a specialist on Russia and the former Soviet states for IHS Global Insight