Gordon Brown has accused the Conservatives of "starting to give up on Scotland" as he claimed the English nationalism adopted by David Cameron's party has left the union on "life support".
The former Prime Minister condemned the "divide and rule" tactics being used by the Tories, arguing that plans for English votes for English laws would "make Scots second-class MPs in the House of Commons".
While he insisted support for independence had not increased since last year's referendum, he called for a constitutional convention to be set up which would make clear the rights and responsibilities of citizens in the different parts of the UK.
But Murdo Fraser, the Scottish Conservative MSP for Mid Scotland and Fife, hit back at the former Prime Minister, saying: "Gordon Brown seems set on going down in history as the man who was wrong about everything.
"The Conservatives have not given up on Scotland - quite the opposite, in fact. We're now the only pro-Union party in Scotland to stand up and take on the SNP while keeping the UK together."