Edinburgh, Scotland (CNN) -- Politicians made their final pleas to Scottish voters Wednesday, the last day of campaigning before they head to the ballot box to vote on independence. Opinion polls put the two sides neck-and-neck ahead of Thursday's historic referendum, which could see Scotland split from the United Kingdom. Voters will be asked the yes/no question: "Should Scotland be an independent country?" The latest poll of polls, released Wednesday by ScotCen, an independent research center, shows "no" at 52% and "yes" at 48%, with "don't know" voters excluded. It is consistent with results over the past week or so, which have indicated the race is too close to call.
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NEW: The latest poll of polls suggests the "no" campaign has a slim lead
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NEW: Scotland's First Minister Alex Salmond: "This is our opportunity of a lifetime"
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Former PM Gordon Brown: "We who vote 'no' love our Scotland and love our country"
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Former UK defense chiefs warn that Scottish independence "will weaken us all"
"The division of the @placeholder may or may not be politically or economically sensible, but in military terms we are clear: it will weaken us all."