By Andrew Osborn
LONDON (Reuters) - Singer Mick Jagger, actress Judi Dench and scientist Stephen Hawking are among 200 British stars who have signed a letter urging Scotland to remain part of the United Kingdom, six weeks before a historic referendum on independence.
The letter, an attempt to sway Scots before the September 18 vote, was organised by "Let's Stay Together", a group which says it aims to give a voice to the millions of Britons outside Scotland who don't have the right to vote.
Only Scots residents can take part in the referendum, meaning people who live in the three other constituent parts of the UK - England, Wales and Northern Ireland - don't have a say.
Opinion polls show most Scots will vote against breaking the 307-year union with England. But they also show that many have not yet decided how they will vote, injecting some uncertainty into the outcome.
The letter, signed by a Who's Who of celebrities, many of them English, was organised by Dan Snow and Tom Holland, well-known TV historians in Britain.
Released at an event on the banks of the River Thames in London close to Tower Bridge, organisers said an extraordinary list of famous Britons had signed the letter, reflecting the fact that non-Scots were not indifferent to Scotland's fate.
"The decision on whether to leave our shared country is, of course, absolutely yours alone," said the letter, which was addressed to "Dear Voters of Scotland".
"Nevertheless, that decision will have a huge effect on all of us in the rest of 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."
Other big names who signed the appeal included actresses Helena Bonham-Carter and composer Andrew Lloyd Webber, singer Cliff Richard, show business impresario Simon Cowell, and actor Dominic West, star of cult U.S. series The Wire.
Between them, organisers said the signatories had 18 Olympic gold medals, 44 Bafta awards, one Nobel prize and two Turner prizes.
Other celebrities, notably singer David Bowie and Harry Potter author JK Rowling, had already spoken out against independence, but not in such numbers and at the same time.
Some pro-independence Scottish nationalists have suggested that the English, who have a long and at times bloody history of rivalry with the Scots, would be glad if Scotland left the UK.
But Dan Snow, a great-great-grandson of British Prime Minister David Lloyd George and one of the letter's organisers, said only a "tiny minority" of English people were indifferent or wanted Scotland to become independent.
"Do English people secretly want them (the Scots) to leave? No they don't," he told Reuters in an interview.
"The impact I hope the letter has is that while Scottish people are rightly debating issues like the NHS (health service), energy, schools and what kind of country they want to be, there's now another category to consider: what the rest of the UK feels."
The pro-independence camp has its own celebrity backers including James Bond actor Sean Connery, actor Brian Cox, and novelist Irvine Welsh.
"Yes Scotland", Scotland's main pro-independence movement, parroted the letter's language to say Scots didn't value being governed by a British government it described as "dreadful".
An independent Scotland could still be "best friends" with the rest of the UK, it said in a statement.
(Editing by Stephen Addison and Raissa Kasolowsky)