nicola sturgeon was booed last night as she refused to rule out holding a second independence vote in the next few years .
two years ago , miss sturgeon said of the independence vote : ` we have always said it 's a once in a generation thing .
she said she would not rule out such a call in the manifesto for the 2016 scottish parliament election .
she said she was ` offering to make ed miliband prime minister ' .