Is it possible that David Cameron has just taken the Labour Party hostage?

Remember that the Prime Minister is a long-standing Euro-sceptic and not averse to leaving the political union in Europe (but not the economic free trade area).

In that respect there is no real split in the Conservative Party - the issue is one of timing, not direction.

By fighting the next election on a Euro-sceptic platform it is possible that he would neutralise the credibility of Ed Miliband and the Shadow Cabinet.