The party may have been arguing beforehand that it was not a victory celebration and the invitations were cautiously marked Elections Results Night, but the banners outside rather gave it away by screaming across the Thames "New Labour New Britain".
Certainly the security was fit for a prime minister and a governing party rather than the leader of the opposition. Hordes of police were gathered at every corner and the man riding his mountain bike up and down the ramps around the concrete jungle of the South Bank was revealed to be a policeman because one of the uniformed officers addressed him as Sean.
In what threatened to be the first public relations gaffe of the new government the press was not being let in until 1am, two hours after the party started. However, after protests press officers came out to welcome in the irate journalists.
With all the MPs still at their counts and Tony Blair not expected until 4am there was a surprise early arrival in Richard Branson, the Virgin boss, who Mr Blair met earlier this week when he rode on one of the new Virgin trains on the West Coast line.
Mr Branson refused to say for whom he votes but said: "This is an historic occasion and I'm looking forward to enjoying the evening. It looks like Labour has won. I think that the country should rally round to ensure they are successful for the next five years."Reuse content