The tent was still there when I left but the VIPs will not now be coming.
The plan was for government officials to spend today signing a raft of documents including the key contract which guaranteed EDF a reward of high prices of Â£92.50 per MWh for the financial risk they are taking with this mammoth project.
But hours after EDF's board voted to approve the Â£18bn power plant on Thursday, the government launched a further review of the project.
This stunning new development came all the way from the top of government and the timing seemed calculated to cause maximum impact.
EDF executives were taken completely off guard, the post-Brexit run of major investment is abruptly halted and what precious entente cordiale in Anglo-French relations there is left after the EU referendum result seems diminished.
Is it a genuine pause for a new government to read the small print of a project that is two administrations old, or a signal of a potential change in policy?
If so - what is plan B?
The nuclear fleet is not getting any younger, renewables are not yet placed to take the strain in January when the sun doesn't shine and the wind doesn't blow. If it's an attempt to get better terms it's a poker game where the stakes are very high.
Down at Hinkley Point yesterday, I watched the EDF Energy staff erect the party tent in preparation for the arrival of VIPs invited to toast the final piece in the nuclear power station puzzle.