On Friday, Galloway took Bethnal Green and Bow in east London, which is dominated by Muslims of Bangladeshi origin, after one of the most heated battles of the British election.
The win by the Scot, nicknamed Gorgeous George for his permanent tan and smart suits, over Labour's Oona King, a black candidate of Jewish origin who previously had a 10,057-vote majority, was a stunning reverse for the ruling party.
Galloway declared his win as a victory for Iraq.
"All the people you killed, all the lies you told, have come back to haunt you," Galloway said in a message to Blair.
"The best thing the Labour Party could do is sack you tomorrow morning," he said to cheers from the audience.
Galloway, a former Labour MP for Glasgow Kelvin who stood for the Respect Party, slammed King as a "poodle" for supporting the war while King ridiculed him for travelling to Iraq before the invasion and praising President Saddam Hussein.
"All the people you (Blair) killed, all the lies you told, have come back to haunt you"
But on the evening, both candidates shook hands and remained gracious.
"Oona King is an able person who will be back in politics and in parliament," Galloway said. "The defeat was not her defeat this evening. It was a defeat for Tony Blair and New Labour and all of the betrayals."
Galloway's victory is indicative of the dissatisfaction felt generally among many of Britain's 1.6 million Muslims.
They voted for the centre-left Blair en masse in 2001 but are now bitter, both over Iraq and a perceived stigmatisation of them since the 11 September 2001 attacks in the United States.
Although making up more than 2.5% of the British population, there are only two Muslim legislators in parliament.
About 52 Muslim candidates were standing in this election.