The Shadow Education Secretary, Pat Glass, has resigned after just two days in the post.
Ms Glass was appointed to succeed Lucy Powell on Monday.
After announcing on Tuesday that she intended to stand down from the role “whenever the next general election takes place”, Glass has decided to quit her “dream job” sooner than planned.
She tweeted saying:
It is with a heavy heart that I have today resigned as Shadow SOS Education. My dream job but the situation is untenable.
Four junior members of the team also resigned on Monday, leaving just one MP – shadow skills minister Gordon Marsden – officially speaking for the party on education issues.