On the 2t of June Mr Cameron, leader of the Tories:
The Conservatives will not let the government “off the hook” on the European constitution, Tory leader David Cameron has insisted.
A bill tabled by Mr Cameron would allow for a referendum on the Lisbon Treaty.
He promised a referendum if he took office before all EU states ratified it, but declined to say what he would do if this happened before a Tory win.
Mr Cameron added that the Conservatives believed in British membership of the EU, but wanted it to be about trade and co-operation “rather than this endless process of building a superstate”.
In an interview with BBC One’s The Politics Show, Mr Clarke - the shadow business secretary and one of his party’s most prominent supporters of Europe - said: “If the Irish referendum endorses the treaty and ratification comes into effect, then our settled policy is quite clear that the treaty will not be reopened.”