The Prime Minister will say today when and where he will deliver his address, which was due to take place last Friday in Amsterdam but was postponed because of the unfolding terrorist incident in Algeria.
Extracts already released show Mr Cameron making clear he wants Britain to stay in the EU but warning that unless Brussels meets the three challenges of dealing with the eurozone crisis, increasing Europe's competitiveness on trade and improving public support, the UK will leave.
While in the extracts he does not mention a referendum, the PM does say the Coalition Government has a "duty to act" on the frustrations of British voters.
Foreign Secretary William Hague said: "We want to succeed in the European Union, we want an outward-looking EU to succeed in the world and for the UK to succeed in that.
"But we have to recognise the EU has changed a lot since the referendum of 1975 and that there have been not only great achievements to the EU's name but some things that have gone badly wrong, such as the euro," he added.
Liam Fox, the former Defence Secretary, seen as a standard-bearer for Conservative eurosceptics, said he was broadly satisfied by the speech.
He said his preference was to have a renegotiated relationship with Europe but that if the EU continued in the same direction with even greater loss of British sovereignty, then "my personal preference would be to leave".
He added: "Ultimately, an in-out referendum has to mean that; that if you vote for whatever the Government is putting forward, that is to remain in on that basis and a no vote would be to leave."