Should the House of Lords leave moral issues as the unique preserve of the Commons?

An editorial in today's Telegraph raises the issue of which chamber should take precedence on moral issues in the context of the debate about assisted suicide:

"It might be thought that MPs who have shown that they cannot behave morally when it comes to their own expenses will struggle when debating one of the burning moral issues of the day. But they must at least try. Capital punishment, abortion, in vitro fertilisation – all have been decided in the House of Commons. It is an abdication of responsibility to leave such "difficult" issues to the House of Lords – or, far worse, the judges."

By convention, the Lords will not overturn manifesto commitments made by a Government, but would it be desirable for there to be a new convention stating that the Upper House would not reverse the will of the elected House on moral issues?

I'm not sure that such a convention would even be feasible to enforce, since everyone would have a different definition of what makes an issue a matter of conscience. What do you think?

Jonathan Isaby