The campaign, hosted at www.marksandspencer.com/PlanA, invites customers, employees, investors, suppliers and anyone concerned about climate change to add to the patchwork with a personal image and a message to those taking part in the Copenhagen negotiations.
The first person to create a 'patch' was Sir Stuart Rose, executive chairman of Marks & Spencer. In his message, Rose said: "Copenhagen is a unique opportunity to do the right thing. Doing nothing is not an option."
Other high-profile 'patchers' that have already shown their support are Zac Goldsmith, Twiggy, Myleene Klass, model Laura Bailey, M&S lingerie model Noemie Lenoir, 'Life on Mars' actor Philip Glenister, and supermodel Erin O'Connor.
Ed Miliband, secretary of the state for energy and the environment, is also supporting the campaign.
Miliband said: "I am happy to see M&S supporting its customers in taking action. That is important because we will need all the popular pressure we can get to strike a deal that is ambitious, effective and fair.
"The world cannot tackle climate change if we leave it to politicians alone. We also need people, companies, charities and every other group in society to act together."
The final quilt and a physical representation will be presented to the government in advance of the summit, which starts on 7 December.
Richard Gillies, director of Plan A, said: "We chose a patchwork quilt as the concept for our campaign because it gives people the chance to be individual. Everyone has different concerns about the effects of climate change, from a fair deal for the poor overseas to preserving the rainforests, but the quilt enables us to bring these under one banner.
"To put it simply, the earth is getting warmer with many damaging consequences. Not taking action, or even delaying action, is simply not an option.
"Our ambition is to reach out to a mainstream audience and demonstrate to those involved in the COP15 event that the M&S family is engaged in the climate change debate. Climate change is no longer a fringe debate, UK high street shoppers care and are demanding action so it's vital that we communicate this."
The campaign was created by London-based agency Digit.
Andy Chambers, Digit's CEO, said: "We were delighted that we could help M&S support this important event in a way that is surprising, involving, and human. Something that could, in a very crowded space, give them their own voice whilst remaining intuitive and familiar."