A performance at the weekend by Brighton-based Elvis impersonator Mark Wright took place at Lodge Park Technology College in Corby as part of a lunchtime speech given by Prime Minister Gordon Brown.
But, according to the LMF, the move contravened the council's own rules because the venue's premises licence only allows entertainment from 6pm until midnight.
The council defended the decision to allow the Elvis impersonator saying that his appearance was not licensable because he was exempt as incidental music.
Health secretary and former culture secretary Andy Burnham, who was also at the event, was at the centre of a previous Licensing Act controversy a couple of years ago when he was accused - again by the LMF - of giving an unlawful performance himself at a Liverpool rehearsal studio by playing Teenage Kicks on a guitar.
The Government held its own consultation on small venues earlier this year to examine whether an exemption should be made for gigs played to 100 people or less.