Shadow business secretary Chuka Umunna made the comments on an exclusive social network website aimed at “the world’s tastemakers”.
The 34-year-old, who posted on the invitation-only site using his middle name Harrison, reportedly complained about the lack of “decent” clubs in the capital.
The Daily Mail reported that in 2006 he wrote: “Most of the West End haunts seem to be full of trash and C-list wannabes, while other places that should know better opt for the cheesy vibe.
In another post on ASmallWorld, which targets wealthy globe-trotting “jetrosexuals”, Mr Umunna called for advice on “what’s hot right now” in Miami.
Mr Umunna has not posted a message on the site since he became MP for Streatham, South London, in 2010 and a spokesman for the politician apologised if the “light hearted” comments caused offence.
The spokesman told the Daily Mail: “Though his user account on the site still exists, he has not posted a thread on the site for many years, since long before he was elected as a Member of Parliament.”
He added: “In terms of the post from 2006, these were comments made on a private social network well over half a decade ago. Though light-hearted in tone and context, and made long before he became an MP, Chuka accepts the choice of words used were not appropriate and apologises if any offence may have been caused.”
Tory MPs lined up to criticise “champagne socialist” Mr Umunna.
Chris Heaton-Harris said: “The secret life of Chuka Umunna has been exposed. In public he likes to portray himself as a man of the people. Yet we know in private he has a lack of respect for the public.
“Chuka, or should I say Harrison, has been outed as the ultimate champagne socialist who revels in living the high life, brands the public C-list celebrities and trashes our capital city.
“You can’t get more out of touch than that.”
Nadhim Zahawi added: “Chuka, like many Labour MPs before him, loves the glitzy wealthy lifestyle, only in secret! If you’ve worked for it and earned it why would you need to hide it? Or is it because it doesn’t go down well with his anti-enterprise lefty Leader?”