Something quite remarkable happened last week. David Cameron proposed a major change to the constitutional fabric of the United Kingdom and barely anyone noticed.

The fact that Cameron’s proposal, subject to a referendum, to let the Welsh Assembly vary income tax rates garnered so little interest is a sign of how inured we have become to constitutional tinkering. But these constant constitutional changes are putting the Union at risk.

If Scotland votes no to independence that won’t, as I say in the column this week, be an end to the matter. Everyone from Cameron to the Better Together campaign have reassured the Scots that if they vote no, more powers will be devolved to them.

Tactically this is the best way to limit the yes vote, but strategically it is a mistake. It not only gives the Nationalists a lever with which to reopen the debate, but compounds the West Lothian Question. To date, the English have been remarkably unbothered by the whole West Lothian issue. But as the backlash over the closure of the Portsmouth shipyard shows, opinion can change quickly. The Union can only bear a certain amount of asymmetry.

Tags: Constitutional reform, David Cameron, England, Scotland, Scottish independence, Union, Unionism, Wales, West lothian question