This is the subject of a referendum that is set to take place on Sept. 18. Scotland has been part of the U.K. for the past 307 years. If the vote passes, the United Kingdom will lose at least 5.2 million citizens.
Scores of supporters have lobbied and even fought for Scotland's independence for centuries. In the 1995 Oscar-winning movie Braveheart, Mel Gibson famously played Scottish freedom fighter William Wallace.
Dench, best known for her role as M in the new James Bond movies, the Rolling Stones frontman, and fellow British stars such as Simon Cowell, Sir Patrick Stewart and Helena Bonham Carter have signed the "Let's Stay Together" petition, which is also supported by more than 13,000 non-famous people.
"The decision on whether to leave our shared country is, of course, absolutely yours alone," the campaign letter states. "Nevertheless, that decision will have a huge effect on all of us in the United Kingdom. We want to let you know how very much we value our bonds of citizenship with you and to express our hope that you will vote to renew them. What unites us is much greater than what divides us."
An Ipsos MORI Scotland poll released this week shows 54 percent of survey respondents who plan to vote in the referendum said they would answer "No" to the question "Should Scotland be an independent country?" About 40 percent said they would vote "Yes."
Absent from the celebrity-backed petition is iconic Scottish James Bond movie alum Sir Sean Connery. He has voiced his support for Scotland to become independent. The 83-year-old star has been living with his family in the Bahamas for the past several years and is ineligible to vote in the Scottish independence referendum because he is not a resident of Scotland. Reuters reported that the actor was mulling the idea of returning if it became an independent state.
"The powers of independence will allow Scotland to develop and enrich its culture as well as marketing it more effectively," he wrote in the New Statesman in March.
British Harry Potter author J.K. Rowling has voiced her opposition to Scottish independence, citing concerns about the economy and the future of medical research, and had earlier this year donated £1 million ($1.68 million) to another pro-unity campaign, "Better Together." She also defended maintaining her stance despite having a Scottish heritage.
"It is true that I was born in the West Country and grew up on the Welsh border and while I have Scottish blood on my mother's side, I also have English, French and Flemish ancestry," she wrote on her website. "However, when people try to make this debate about the purity of your lineage, things start getting a little Death Eaterish for my taste."