London 2012: Strike threat by Unite to Olympic Games
Len McCluskey, of the Unite union, also called for civil disobedience during the Games to defend public services.
In an interview with the Guardian, Mr McCluskey said his union had discussed the possibility of strike action but there were currently no plans in place.
Conservative co-chairman Baroness Warsi said she was "shocked" by his comments.
Mr McCluskey said: "If the Olympics provide us with an opportunity, then that's exactly one that we should be looking at."
The union boss added: "The attacks that are being launched on public sector workers at the moment are so deep and ideological that the idea the world should arrive in London and have these wonderful Olympic Games as though everything is nice and rosy in the garden is unthinkable.
'Right to protest'
"Our very way of life is being attacked. By then this crazy Health and Social Care Bill may have been passed, so we are looking at the privatisation of our National Health Service.
"I believe the unions, and the general community, have got every right to be out protesting."
Mr McCluskey said the purpose of protest was "to bring your grievances to the attention of as many people as possible".
Baroness Warsi said it was "an appalling display of naked self-interest" - and called on the Labour leader to intervene.
"The London Olympics will be a great occasion for this country. It is disgraceful for a trade union boss to be calling for mass disruption when the eyes of the world will be on Britain," she said.
"I am shocked that Unite would sink so low as to spoil this great national event for everyone else. Ed Miliband must urgently order his union cronies to rule out disrupting the Olympics."
Shadow Olympics minister Tessa Jowell said no athlete or visitor would understand or sympathise with any disruption.
She said: "If this is a negotiation it should take place in private. Unions and employers should get together and sort it out without threats or disruption to Britain's Olympics."
In an interview with the Guardian, Mr McCluskey said his union had discussed the possibility of strike action but there were currently no plans in place.
Conservative co-chairman Baroness Warsi said she was "shocked" by his comments.
Mr McCluskey said: "If the Olympics provide us with an opportunity, then that's exactly one that we should be looking at."
The union boss added: "The attacks that are being launched on public sector workers at the moment are so deep and ideological that the idea the world should arrive in London and have these wonderful Olympic Games as though everything is nice and rosy in the garden is unthinkable.
'Right to protest'
"Our very way of life is being attacked. By then this crazy Health and Social Care Bill may have been passed, so we are looking at the privatisation of our National Health Service.
"I believe the unions, and the general community, have got every right to be out protesting."
Mr McCluskey said the purpose of protest was "to bring your grievances to the attention of as many people as possible".
Baroness Warsi said it was "an appalling display of naked self-interest" - and called on the Labour leader to intervene.
"The London Olympics will be a great occasion for this country. It is disgraceful for a trade union boss to be calling for mass disruption when the eyes of the world will be on Britain," she said.
"I am shocked that Unite would sink so low as to spoil this great national event for everyone else. Ed Miliband must urgently order his union cronies to rule out disrupting the Olympics."
Shadow Olympics minister Tessa Jowell said no athlete or visitor would understand or sympathise with any disruption.
She said: "If this is a negotiation it should take place in private. Unions and employers should get together and sort it out without threats or disruption to Britain's Olympics."