"Apart from 70 members of the (Islamic) revolution faction, which backs Ahmadinejad, only 30 other principalists (conservatives) turned up," the reformist Etemad Melli newspaper said, adding that 100 boycotted the event.
"Ali Larijani and his deputies were not there," conservative MP Javad Arianmanesh was quoted as saying of the Wednesday evening event.
Larijani, Iran's former chief negotiator, was elected speaker in May 2008 and has emerged as a conservative rival to Ahmadinejad.
It is not known whether the invitation to the dinner was extended to all 290 members of the conservative-dominated parliament, where opposition reformists and independents hold about 90 seats.
"If Ahmadinejad remains in Pastor (the street where the presidential official is based) his ministers will have a hard time winning a vote of confidence from parliament," said Etemad Melli.
The newspaper belongs to the party of Mehdi Karroubi, a reformist former parliament speaker who came a distant fourth in the disputed June 12 poll.
Despite being dominated by conservatives, the parliament has clashed with Ahmadinejad on several occasions, notably over his economic policy.
The house also impeached his former interior minister Ali Kordan last year for faking an Oxford degree and lying.
