A contrite Labor MP has apologised unreservedly for using the House of Representatives as a platform to complain about the size of a portion of beef stroganoff served to his wife in the parliamentary cafeteria.

- Labor MP 'sorry'

- Stroganoff 'too small'

- Raised in Parliament

John Murphy, member for the NSW seat of Lowe and Parliamentary Secretary to the Minister for Trade, called for an investigation this week into serving sizes following his wife's dissatisfaction with a beef and rice dish she had ordered for lunch.

His wife had earlier complained to cafeteria staff about at the small amount of hot food available after 7pm.

"My wife was told by cafeteria staff that management had told staff they had been serving big food portions and the manager had instructed them to make the portions smaller," Mr Murphy told Parliament.