UPDATE: Labour leader Jeremy Corbyn has named Karl Turner shadow attorney general, just hours after Catherine McKinnell resigned the post.
McKinnell's resignation was just the latest setback for Labour, which has suffered a spate of resignations following Corbyn's recent reshuffle.
In a letter to Corbyn published earlier today, McKinnell said: "I have found it increasingly difficult not to be able to speak up in the commons about matters that are of huge importance to my constituents."
McKinnell said she that while she respects Corbyn personally, she had concerns over "the direction and internal conflict within the Labour party", which she fears is taking it down an increasingly negative path.
Separately, Paula Sherriff also resigned as parliamentary private secretary to Jon Trickett, shadow communities and local government minister, earlier today.
Last week Corbyn embarked on his front bench shake-up, which some critics labelled a "revenge" reshuffle.
Corbyn defended his reshuffle on BBC Radio 4's Today program this morning, despite claims that he abandoned his so-called new politics and instead returned to the old politics of splits and resignations.