The SNP could be on course for unexpected defeats in Perthshire and Angus, with tight results predicted.
A Conservative source said they had “already heard the word recount mentioned” in Mike Weir’s seat, where Kirstene Hair is the main challenger.
Other Tory insiders were increasingly confident of ousting Pete Wishart from Perth and North Perthshire.
Alyth-born MEP Ian Duncan is the candidate seeking to replace him as representing the constituency.
It was looking like better news for the Nationalists in North East Fife, however, with Stephen Gethins, the party’s Europe spokesman, looking likely to see off a two-pronged attack from the Liberal Democrats and Tories.
Meanwhile, Kirkcaldy and Cowdenbeath, the seat of former Prime Minister Gordon Brown, was described as “tight” by an SNP source.
Roger Mullin broke the BBC swing-o-meter in 2015 as he claimed the seat with a majority of almost 10,000 but it appears Lesley Laird, the former deputy leader of Fife Council, is snapping at his heels.