Unsurprisingly, the show devised by Oscar-winning British director Danny Boyle drew accusations from the British political right that it had strayed into "leftie" issues.
Aidan Burley, a lawmaker from Prime Minister David Cameron's ruling Conservative party, tweeted: "The most leftie opening ceremony I have ever seen -- more than Beijing, the capital of a communist state! Welfare tribute next?"
He followed that with: "Thank God the athletes have arrived! Now we can move on from leftie multi-cultural crap."
Several people tweeted their support for his comments.
Alastair Campbell, former British Labour prime minister Tony Blair's communications chief, retorted on Twitter: "Brilliant that we got a socialist to do the opening ceremony."
Cameron's Downing Street office distanced itself from Burley's comments, tweeting a message from the premier reading: "The opening ceremony has been a great showcase for this country. It's more proof Britain can deliver."
Burley was removed from his job as aide to the transport minister last month after attending a Nazi-themed stag party in a French ski resort.
Ahead of the show, Boyle -- whose film "Slumdog Millionaire" won eight Oscars in 2009 -- denied he was pushing a political agenda.
"The sensibility of the show is very personal," he said.
"A group of us have created it, but we had no agenda other than... values that we feel are true.
"Not everybody will love that but people will be able to recognise as being honest and truthful really. I felt that very strongly. There is no b(expletive) in it, and there is no point-making either."
The show bringing the curtain up on the London Olympics began with sections showing idyllic rural Britain being overtaken by the Industrial Revolution, before moving on to a 10-minute sequence celebrating the state-run National Health Service (NHS).
Britain's first televised lesbian kiss -- from a 1993 episode of soap opera "Brookside" -- was shown in a fast-moving montage of flim and TV clips.
Later in the ceremony, dancers formed the shape of the Campaign for Nuclear Disarmament badge and other performers represented the struggle of trade union movements.