Almost one year to the day of the in/out referendum, East Dunbartonshire MP and Business Minister Jo Swinson said Scotland had a "momentous" decision to make, as she issued a rallying cry to the party's members.
Ms Swinson described the vote, which will be held on September 18 2014, as "the most important" of her life.
Formally opening the Lib Dem party conference in Glasgow, she said: "In just over a year, people in Scotland have a momentous decision to make. It will be the most important vote that I've ever cast and that's true of people my people's generation too, because separation isn't a protest vote, it's a massive, life-changing decision that can't be undone."
Ms Swinson took the opportunity to criticise SNP leader and Scotland's First Minister Alex Salmond, saying he "thinks he has all the answers".
She said she was "angry" that the SNP had failed to follow the example of the coalition Government in helping the disadvantaged.
Addressing delegates and referencing the party's conference motto, she said: "And that's why Liberal Democrats, it's so important that we achieve our vision of a stronger economy and a fairer society."
She said: "It's why we are cutting taxes for the low paid, increasing incentives to work, cracking down on payday lenders and calling time on rogue employers who exploit and underpay their workers. And it's why I feel so angry that many of the other good things that we are doing in government, don't reach people here, because of the stubborness of the SNP government in Scotland."
She also criticised the Labour Party for taking their support in Scotland "for granted, for so long". She said the party had failed to deal with the inequality problems in the country and vowed her party would continue to do more to combat health and income deprivation, faced by parts of Glasgow.
She said: "It is right with devolution that these decision are made in Scotland, but just because we can do something differently it doesn't mean we always have to. Alex Salmond thinks he has all the answers, but the truth is different parts of the UK can learn from each other.
"Scotland and the rest of the UK are stronger together economically, sharing the risks in the bad times and enjoying the opportunities when things go well. Through the EU and the United Nations, we can achieve more if the UK is together than split apart. And 300 years of shared culture, heritage and family ties should not be tossed lightly away. The vote will be decided here in Scotland, but the debate will rage across the entire UK."
Ms Swinson called on Lib Dem members to help in the campaign to keep Scotland part of the UK.
"Whether it's campaigning here in Scotland or on the telephone or engaging with Scottish friends and family ... the voice of the rest of the UK also making the positive case for Scotland to stay is an important one that needs to be heard," she said.