Opposition leader Vitali Klitschko was met with boos and whistles from a crowd of anti-government protesters who filled Kiev's Independence tonight, as he attempted to convince them signing a peace deal with the Ukrainian government was the correct course of action.
The former heavy-weight champion told ITV News' Europe Editor James Mates he had signed the EU-backed peace deal because he "had to stop the fighting".
More than 70 people have died during clashes between government forces and protesters in the past week.
But protesters were hopeful an agreement would mean the end of President Viktor Yanukovich's tenure. Instead the President has agreed to early elections and a Coalition government.
The opposition's minds were concentrated by Poland's foreign minister, who'd helped negotiate the deal, who told them martial law may be the next step.
ITV News' Europe Editor James Mates reports:
The agreement was welcomed by the Western world but met with trepidation from Russia.
International leaders will do all they can to ensure the deal struck in Ukraine to end the bloodshed is successful, David Cameron has said.
Mr Cameron said the deal offered a "real chance" to bring peace back to the nation and end the "truly shocking" carnage that has spiralled since anti-government demonstrations kicked off three months ago.
But Russia said their were still questions over the deal and the country's envoy in Kiev did not sign the agreement.
"Certain questions still remain, consultations will continue, this is a normal process," Interfax quoted Vladimir Lukin as saying after returning to Moscow.
Today Ukraine's government also dismissed its acting Interior Minister Vitaly Zakharchenko for using "violence" against protesters during the wave of street unrest.
Zakharchenko is a hated figure on Kiev's Independence Square because of several police crackdowns on anti-government protesters. His dismissal will be seen as a victory for the protest movement.
And in a boost for the opposition movement, the Ukrainian Parliament amended a criminal code which could pave the way for the release of jailed opposition leader Yulia Tymoshenko.
MPs voted 310-54 to decriminalise the count under which she was imprisoned, meaning that she is no longer guilty of a criminal offence.
"Free Yulia! Free Yulia!" MPs chanted after the vote.
It's not immediately clear when she might be released from the eastern city of Kharkiv where she is serving her sentence.
Tymoshenko was an architect of Ukraine’s 2004 Orange Revolution that promoted democracy and unsuccessfully ran for president in 2010.
She was sentenced to seven years in prison in October 2011, when she was found guilty of exceeding her powers while negotiating a gas contract with Russia while she was prime minister.