The decision comes after the council was labelled “illiberal’ and ‘morons’ by an outraged Twitter mob.
Roddy McCuish, the council leader, told BBC Radio 4 that he was reversing the ban.
“There’s no place for censorship in Argyll and Bute council and there never has been and there never will be.
“I’ve just instructed senior officials to immediately withdraw the ban on pictures from the school dining hall. It’s a good thing to do, to change your mind, and I’ve certainly done that.”
Martha, whose blog, NeverSeconds, was attacked by the council in a statement released earlier in the day in which it appeared to accuse the nine-year-old of “unwarranted attacks on its schools catering service”.