The Evening News has done a profile on Edinburgh Central. In it under-threat Labour incumbent admits that people are thinking about the SNP. How interesting. I seem to remember the struggling Labour campaign in Dunfermline talking up the SNP as their main rivals when they knew perfectly well that their support was haemorraging to Willie Rennie. In 2005 the struggling Labour campaign in Edinburgh South talked up the Tories as their main rivals when they knew Marilyne MacLaren was breathing down Nigel Griffith's neck. In fact, Marilyne was just 405 votes behind.
The moral of the story is that a vote for the SNP in places like Edinburgh Central and Dunfermline West might as well be votes for Labour.
Labour knows that Siobhan Mathers is on course to win and the only thing that will save their skin is an increase in the SNP vote.