English politicians are terrified of Scottish independence. They would be facing the unknown. Would the Scottish economy boom, as did that of Slovakia once it separated from its richer Czech neighbour? Would Scotland join the euro? Would they refuse to have English nuclear weapons (Trident) on their territory? Would they turn into a tax haven, like the Isle of Man and the Channel Islands (and they only have "devo max")? Would Scotland simply do better?
The Labour & Unionist Party would have to totally re-think and re-organise. It would no longer have a role at Westminster as the representative of the Scottish Interest. It has no standing in Northern Ireland, not enough in Wales - and not enough in England.
The Conservative & Unionist Party would have different problems. To present itself as an English party would run it into trouble with its own Unionist elements and our ruling Royal Family.
England would be stuck with a broken-backed Union with Northern Ireland and Wales, neither of which enthuses English voters who choose Dublin and Edinburgh for their weekend breaks, not Belfast or Cardiff.
Reform would be forced upon the House of Lords.
Shake-up and uncertainty is absolutely the best thing which could happen to England, upsetting the complacent and corrupt routines of Westminster politics