Buoyed by the success of the tactic in May's Westminster election, the Unionists are already fighting next May's Scottish general election on the scaremongering tactic of "Vote SNP; get another referendum".
This tactic is designed to put the National party on the spot. Admit to a second referendum, and it'll scare SNP-voting No voters off, goes the thinking. Deny it, and put Yes voters off the Nationalists in enough numbers that it splits the Yes vote and allows Labour through the middle to deny a pro-independence majority.
As far as I can tell, there is one relatively simple way for the SNP to defeat this tactic. In its manifesto, a promise: "the people of Scotland gave their opinion on the Constitutional settlement in September 2014. We respect that decision. Should this party win a majority, there will be no referendum on independence called by the Scottish Government, under any circumstances, in the Fifth Parliament. However, should there be a material change in circumstances provoked by the actions of the British government, this Government will resign, and will oppose any alternative government. If, in accordance with the Scotland Act, this leads to early elections to the Sixth Parliament, we reserve the right to campaign in that election on a platform of holding a new referendum to take into account the changed circumstances".