"If the Tories [Conservative party] win, as is feasible, then the UK will be faced with an in-out referendum on the EU… If that vote is to leave the EU, then provided the SNP has campaigned for a mandate, the Scottish Government will have a democratic majority to retain membership the EU through a declaration of independence," Gordon Wilson said in a statement.
Wilson added that economic arguments would be in favor of Scotland staying with Europe, rather than "going over the economic cliff with London."
Scottish voters opted to remain part of the United Kingdom by a majority of 55 percent to 45 percent in a referendum held last September.
Since that result, the SNP, which backed independence for Scotland and which controls the Scottish Government and a majority in the Scottish Parliament, has seen a significant rise in its popularity.
Widespread speculation of another UK hung parliament following the next UK General Election to be held on May 7 has led to some senior politicians warning that the SNP could be on course to become the third largest political party in Britain, despite only running candidates in Scotland.