Last week, the prime minister decided to reject calls from the likes of German chancellor Angela Merkel and French prime minister Nicolas Sarkozy who wanted him to agree to the implementation of a new EU treaty.
Mr Cameron used his veto on this proposal on the grounds it would not suit the UK - a step many saw as an historic move away from European political power as Britain is now isolated from the other 26 member states.
However, the leader has told Parliament this measure will not act as any sort of precursor towards the UK departing the bloc.
"Britain remains a full member of the EU and the events of the last week do nothing to change that. Our membership of the EU is vital to our national interest," he insisted.
By Asim Shah