The British government began a historic transfer of powers to Scotland on Thursday, keeping a pledge it had given to persuade Scots to reject independence as renewed nationalist support surges.

The draft bill, to be enacted after a general election on May 7, will further dismantle Britain's highly centralized system of government, a move that critics fear could trigger the beginning of the end of the U.K.

It has already spurred demands from some politicians for similar moves in England, Wales and Northern Ireland, teeing up political uncertainty and heralding an eventual redistribution of power in the world's sixth-largest economy.